Achiote is the seed of Bixa orellana, a shrubby tree native to tropical America. The seeds are the size of small peppercorns and sit inside a spiky red pod that looks alarmingly like a rambutan. Crush them and they release a fat-soluble pigment called bixin that stains anything it touches a deep, almost neon terracotta.

For centuries before the Spanish arrived, the Maya used achiote as body paint and food colouring. Today it plays both roles. It is the dye in cochinita pibil, in tacos al pastor, in Filipino kare-kare, in Jamaican rice-and-peas, in supermarket cheddar in the United States, and, until recently, in the wax coating of Babybel. The flavour is subtle, earthy, faintly peppery, with a whisper of nutmeg. On its own it is quiet. Blended with garlic, cumin, oregano and vinegar into the Yucatec recado rojo, it becomes the backbone of a regional cuisine.

The seeds are hard as gravel and useless raw. They need to be softened, either by grinding in a spice mill, by soaking in warm vinegar or lime juice, or by frying gently in fat, which is called achiote oil and is the standard way Latin American home cooks extract the colour. A tablespoon of achiote seeds in a cup of hot oil, strained after a few minutes, gives you a brilliant orange cooking fat for rice, sofrito, or the top of a tamale.

Do not confuse achiote paste with achiote powder. The paste, sold in red bricks in Mexican markets, is already seasoned and is what Yucatec cooks buy for cochinita. The powder is just ground seed and is a raw ingredient, not a finished spice mix.

On our Yucatán tours you'll see achiote in the market as pods, seeds, powder and brick paste, all in the same stall, and taste it in the same dish four different ways.

Ají amarillo is a Peruvian chilli, Capsicum baccatum, and despite its name (yellow chilli) it ripens to a deep, glowing orange. It is medium hot, roughly 30,000 to 50,000 Scoville units, which puts it well below a habanero but above a jalapeño. The heat is not the point. What matters is the flavour: floral, fruity, faintly citric, with a specific top note that anchors so much of the Peruvian kitchen that Gastón Acurio has called it 'the soul of Peruvian cooking'.

The chilli grows only in the Peruvian coastal valleys and the highland areas of the Andean sierra. It has been cultivated for at least 2,000 years, and archaeological digs at coastal Peruvian sites have turned up dried ají pods in pre-Inca burial layers. It did not travel widely during the Columbian exchange, which is why it is barely known outside South America even though it is the defining chilli of one of the world's great cuisines.

In the market it appears in three forms. Fresh, glossy and shoulder-length, sold in bunches. Dried and shrivelled, called ají mirasol, with a deeper smokier flavour used for stews. And puréed, sold in plastic pots as pasta de ají amarillo, which is the form most restaurant kitchens use. The purée is what goes into ají de gallina, the shredded-chicken dish thickened with bread and walnuts, and into papa a la huancaína, the potato dish drenched in a bright yellow sauce of ají, evaporated milk and queso fresco. It is also the essential chilli in the base of a proper leche de tigre for ceviche.

Fresh ají amarillo is nearly impossible to find outside Peru. Frozen whole is the next best thing. Ají amarillo paste in jars, sold in Latin American shops, is a fine everyday substitute and keeps well. Do not try to substitute a scotch bonnet or a fresno; the flavour is completely different, and the resulting dish will taste of chilli generally, not of ají amarillo specifically.

On our Lima, Cusco and Arequipa tours we take you to a market where you can taste ají amarillo three ways, fresh, dried and puréed, so you understand what distinguishes it.

Asado is both a technique and a social event, and in Argentina and Uruguay the two are inseparable. It is a Sunday-lunch tradition, a family gathering, a national identity, and, occasionally, a competitive sport. It is also the specific method of grilling meat over hardwood coals on a parrilla (a slatted iron grill above a bed of embers) or on a cross (asado al asador, meat splayed on a long metal cross set up beside an open fire).

The wood matters. Argentinian and Uruguayan asadores use quebracho, algarrobo, or espinillo, all dense hardwoods that burn hot and clean and produce very little smoke. The wood is burned down to glowing embers in a separate section of the grill, then shovelled underneath the meat in small quantities as needed. The heat is low. Asado is slow cooking, not fast searing. A whole flank might take three hours. A pig on the cross can take six.

The cuts and their order are traditional. First on the grill are the chorizo and morcilla (blood sausage), then the achuras (offal, including chinchulines, mollejas and riñones), then the ribs (asado de tira, cut across the bone in wide bands), and finally the larger prime cuts (bife de chorizo, entraña, vacío, tapa de asado). The whole progression takes hours and is served in courses, with the asador standing at the grill throughout, in charge of everything.

The seasoning is minimal. Salmuera, a brine of salt and water, is brushed onto the meat as it cooks. No marinades, no rubs, no olive oil, no herbs on the grill. The flavour is meat, smoke, salt and time. Chimichurri appears at the table for those who want it, but many purists eat the meat plain.

The social choreography is as fixed as the cooking. The asador does not sit down. Everyone else drinks Malbec, picks at provoletas (a grilled cheese starter) and empanadas, and waits for the courses to appear. The eating goes on for hours. Coffee and a small dessert (dulce de leche something) close the meal.

On our Buenos Aires and Mendoza tours we take you to a full family asado on a Sunday, with the fire lit at midday and the meat not finished until sunset.

Bánh mì is a Vietnamese sandwich, but the word itself just means 'bread'. The French left Vietnam a baguette and the Vietnamese spent a century improving it. The Vietnamese baguette is shorter and lighter than a Parisian one, with a much thinner and shatter-crisp crust and a huge, airy crumb. It is baked with a fraction of the wheat, often cut with rice flour, which is what gives it the paper-thin shell and the empty middle. That emptiness is the point. It leaves room for filling.

A classic bánh mì thịt nguội, the pork and pâté version, contains chả lụa (a springy pale pork sausage), a slice of pâté, a smear of rich butter or Kewpie-style mayonnaise, cha bong (pork floss), thịt nướng (grilled pork), pickled daikon and carrot, cucumber batons, sprigs of coriander, sliced chilli and a drizzle of Maggi seasoning or soy sauce. The whole thing is squeezed shut and eaten standing up.

The structure is deliberate. Fat, salt, acid, heat, herb, crunch. Every mouthful hits all six. The pickled vegetables cut the pâté. The coriander freshens the pork. The chilli lifts the mayonnaise. The crackle of the crust holds the whole architecture together. It is one of the most efficiently balanced sandwiches on the planet.

There are regional variations. Saigon bánh mì is the busiest and most maximalist, and probably the version most people know. Hanoi bánh mì is often simpler, sometimes just pâté and cucumber, or a warmed-through banh mi chao with egg. Hoi An has a fanatical local scene, popularised abroad by Anthony Bourdain's visits to Bánh Mì Phượng and Bánh Mì Madam Khanh. Bánh mì xíu mại is a Dalat speciality, the sandwich served open with pork meatballs in tomato broth on the side.

On our Ho Chi Minh City tour we take you to a bakery where the baguettes come out of the oven every ninety minutes, still hissing, and get filled in front of you in the time it takes to hand over 20,000 dong.

Berbere is an Ethiopian spice mix and, along with niter kibbeh (spiced clarified butter), it is one of the two engines of Ethiopian cooking. It is a coarse red powder, chilli-forward, warm rather than blistering, and it is the base of doro wat, siga wat, misir wat and most of the other red stews that arrive on a shared injera platter.

The composition varies by household and region but almost always includes red chilli (specifically Ethiopian mitmita chilli, or a similar variety), garlic, ginger, dried basil, korerima (Ethiopian cardamom, a close relative of black cardamom), long pepper, fenugreek, ajwain (Ethiopian caraway), cinnamon, clove, nutmeg, allspice and salt. Some versions include sun-dried onion, some add bishop's weed, some include rue. The heat level is moderate on the Scoville scale but the perceived spice on the tongue is much higher because the mix contains so many other warming spices reinforcing the chilli.

Traditional berbere is a two-day project. Whole ingredients are soaked, sun-dried, dry-roasted, and then ground on a mortar or milled together. In markets across Addis Ababa and Mekelle, spice merchants blend berbere to order, and the resulting mix reflects the family's or the merchant's own preference. There is no supermarket-standard berbere in Ethiopia, and buying one that has been sitting in a jar in a European supermarket for six months is a poor substitute.

The technique of using it is important. Berbere is almost always cooked in fat, not stirred in raw. The most common opening move in an Ethiopian recipe is a long, slow browning of finely chopped red onion in niter kibbeh or oil (called qulet), for anywhere from 30 to 90 minutes, followed by the addition of a heaped spoon or two of berbere, which is bloomed briefly in the hot fat before the main ingredient joins. That bloom is essential. It rounds and deepens the flavours and, crucially, tames the raw chilli note that berbere carries fresh from the pot.

On our Addis Ababa tour we visit a mercato spice merchant who has been blending his own berbere for three decades, and then take you to a lunch stall where the doro wat has been on since 6am.

Ceviche (also spelt cebiche or seviche, and locals will fight you on the correct one) is the national dish of Peru. It is raw fish, cut into cubes, cured briefly in lime juice, and dressed with red onion, aji chilli, salt and coriander. Served in a shallow bowl with a piece of boiled corn on the cob (choclo) and a wedge of sweet potato (camote) to balance the acid, it is one of the great cold dishes on the planet.

The chemistry is fun. The citric acid in the lime juice does not cook the fish in the strict sense (no heat is applied), but it does denature the proteins on the surface of the fish, turning them opaque and firm in a way that looks and eats like cooked flesh. The technique probably has pre-Hispanic roots, using local fermented juices and chicha, but the acid-cured version we recognise today emerged after Spanish sailors introduced sour Seville oranges, later replaced by limes.

The key argument in Peruvian ceviche is time. The old school, which dominated until the 1970s, marinated the fish for hours, producing a fully white, firm, more preserved product. The modern school, championed by Gastón Acurio and the nikkei chefs who reshaped Lima's dining scene, cures the fish for two or three minutes, so the outside is opaque but the inside stays translucent and sashimi-like. The modern school won.

The liquid at the bottom of the bowl, called leche de tigre (tiger's milk), is a mixture of lime juice, fish juice, aji, garlic, coriander and salt. It is not a garnish. It is often served on the side in a small glass to be drunk after the fish is eaten. In coastal Peru it has a reputation as both a hangover cure and an aphrodisiac, claims that are treated with more reverence than they perhaps deserve.

Peruvian coastal ceviche uses corvina or lenguado, plated with sliced red onion, aji limo, choclo, camote and sometimes a slick of cancha (fried maize kernels) for crunch. Ecuadorian ceviche is looser, often served with tomato juice or shrimp broth. Mexican ceviche leans on tomato and avocado. All three deserve their own paragraph, but the Peruvian version is the ancestor.

On our Lima tour we take you to a cevichería in the port district of Chorrillos, where the fish is landed at dawn and served in a bowl by noon.

Chapulines are grasshoppers, specifically several species of Sphenarium collected in the alfalfa fields of the central valleys of Oaxaca. They are eaten in Mexico the way peanuts are eaten in a British pub, by the handful, with beer, as something to keep the conversation moving. The good ones are salty, smoky, faintly citric, and about the size of a small prawn.

The preparation is straightforward. The insects are cleaned, purged for a day in water, boiled briefly, then toasted on a hot comal with lard, salt, lime juice, minced garlic and a pinch of chile pasilla or chile de árbol. The heat crisps them and drives off the raw grassy note, leaving something closer to a pork rind than to an insect. The colour deepens from grey-green to a rusty red as they cook, and the smell in the kitchen is meaty and toasty, not at all what a first-timer expects.

They are eaten straight, folded into a tlayuda, dropped into a mezcal on the rim of the glass, ground into a salsa, or blended into a butter for smearing on tortillas. Nutritionally they are close to being pure protein, and they contain more iron per gram than beef. Ecologically they are unmatched. They take almost no water to raise, they are harvested wild in the same field that produces the alfalfa, and they arrive at the market in a bag that a child can carry.

Cortés wrote about chapulines in the 1520s. Pre-Hispanic peoples had been eating them for at least two thousand years. The habit never went away in Oaxaca, and in the last decade it has spread. You now find chapulines in a handful of restaurants in Mexico City, Los Angeles and even Copenhagen.

On our Oaxaca tour we start you gently, with a small bowl of chapulines on the rim of a mezcal, in a mercado 20 de Noviembre stall that has been toasting them the same way since the 1950s.

Char siu is Cantonese barbecue pork, and the name literally means 'fork-roast', a reference to the long forks that skewer the long strips of pork before they are hung inside a tall cylindrical charcoal oven. The classic cut is pork shoulder or belly, trimmed into long batons that cook in about 40 minutes, developing a deep mahogany crust while staying juicy in the middle.

The marinade is the whole show. It is a red-tinted mixture of maltose (or honey), soy sauce, hoisin, oyster sauce, shaoxing rice wine, five-spice powder, garlic, sesame oil, and, traditionally, a small amount of red fermented bean curd (nam yu) that gives char siu its particular ruby-pink glow. Modern shops sometimes cheat with red food colouring, which is a shortcut and, honestly, usually detectable, because the flavour is thinner.

The technique matters as much as the marinade. The pork is marinated overnight, then hung inside the oven with a tray beneath to catch the drips, and cooked over intense heat until the surface starts to caramelise. Halfway through the cook, it is brushed generously with maltose syrup, which is what produces the shiny, faintly sticky lacquer. If you do not brush, you do not get the glaze. If you brush too early, it burns. This is a technique that takes years to get right, which is why char siu masters in Hong Kong are treated as craftsmen rather than cooks.

It is eaten in three main ways. Sliced over rice with a scoop of blanched greens and a spoonful of the roasting liquid, as char siu fan. Chopped into a fluffy sweet bun as char siu bao (in the steamed version) or char siu sou (the baked one). Or piled onto a bowl of egg noodles with wonton, as the classic char siu wonton mein.

The best char siu in Hong Kong is a topic of endless argument. Joy Hing in Wan Chai, Kam's Roast in Wan Chai, Yat Lok in Central, Sun Kwai Heung, Hay Hay Kitchen, and any number of hole-in-the-wall siu mei shops in the older neighbourhoods all have serious claims. On our Hong Kong tour we take you to a master in Sheung Wan whose cha siu has been ruining people for other pork for decades.

Chermoula is a Moroccan marinade, essentially the North African cousin of the Latin American chimichurri. It is bright green, loose, uncooked, and built around fresh coriander, flat-leaf parsley, garlic, cumin, sweet paprika, ground coriander seed, saffron or turmeric, olive oil and lemon juice, sometimes with the addition of preserved lemon peel and a spoonful of harissa for heat. Every family, every region and every fisherman has a slightly different balance.

Its natural partner is fish. In Essaouira, the sardine capital of Morocco, chermoula is what you rub between the flaps of a whole butterflied sardine before it goes on the charcoal grill. In the same town, larger fish (mullet, sea bream, sea bass) are slit, packed with chermoula, wrapped in a banana or palm leaf and grilled or baked. The marinade tenderises the flesh, cuts the oiliness of the fish, and turns bright green as it hits the heat.

But chermoula is not only for fish. It works on chicken kebabs, roast vegetables, lamb chops, or as a dipping sauce for warm khubz bread. Some versions are pounded to a smooth paste in a mortar for use as a marinade. Others are chopped by hand and left loose, more like a salsa verde, to spoon over grilled food at the last minute.

The regional variations are worth noting. Tunisian chermoula is drier and more preserved-lemon-forward, closer to a paste, and often used with dried fish. Algerian chermoula is heavier on cumin. Moroccan Atlantic-coast chermoula, from Essaouira and Safi, leans on saffron and fresh coriander. Amazigh (Berber) versions from the interior sometimes omit fresh herbs entirely and rely on cumin, paprika and preserved lemon.

It should be made the day it is used. Fresh coriander and parsley oxidise fast, and a chermoula left overnight in the fridge loses the sharp green top note that makes it worth eating in the first place.

On our Essaouira and Marrakech tours we watch a fisherman brush chermoula onto whole sardines straight off the boat and grill them over charcoal on the harbour wall.

Chimichurri is the classic Argentinian sauce for grilled meat, and after asado itself it is probably the most recognised item in the country's culinary export catalogue. It is uncooked, sharp, herby, garlicky, and it exists to cut the richness of the fatty beef that comes off a South American parrilla. The etymology is unresolved. There is a popular story that it derives from the name of an Irishman called Jimmy McCurry, and another that it comes from a mangled Basque phrase. Neither is likely, and the truth is probably a Quechua or Guaraní root now lost.

The recipe, roughly, is chopped flat-leaf parsley, minced garlic, dried oregano, red wine vinegar, water, olive oil, salt, and a pinch of red chilli flake or aji molido. Ratios vary. Some cooks add fresh coriander (in Uruguay and Paraguay), some add cumin (in northern Argentina), some finish with fresh oregano leaves. What everyone agrees on is that it must be loose, not thick, and that the herbs must be chopped by hand, not blitzed in a food processor. A machined chimichurri turns into a green paste. A hand-chopped one stays as a rustic vinaigrette with distinct flecks of leaf and garlic.

Chimichurri rojo, the red version, adds tomato and red pepper for a milder, sweeter sauce more often served with sausages or chorizo. Chimichurri verde, the classic green, is the standard on any parrilla table. Both are served in a small dish, spooned over slices of steak or into a choripán as it is passed across the grill.

It should sit for at least an hour before serving, ideally two, so the flavours marry. Made too fresh, it tastes raw and aggressive. Made too far ahead, the parsley oxidises and the sauce turns brown. Argentinian home cooks make it in a jar in the morning for that evening's asado.

Chimichurri is not gravy. It is not a dipping sauce for chips. It is a specific sharp counterpoint to grilled beef, and it belongs beside a rare, salty, wood-charred slice of bife de chorizo. On our Buenos Aires tour we take you to a parrilla in Palermo where the chimichurri is made in the morning and served by the ladleful.

Cochinita pibil is a Yucatec dish, not a general Mexican one, and it is one of the oldest recipes still in daily circulation on the peninsula. The word pibil comes from the Mayan pib, meaning a hole dug in the ground and lined with hot stones. That is the original oven. The whole pig, or in the modern version a shoulder, is rubbed with a paste of recado rojo (achiote seed, garlic, cumin, allspice, oregano, black pepper), doused in the juice of naranja agria (bitter Seville orange), wrapped tightly in banana leaves, and lowered into the pit for eight to twelve hours.

The chemistry is beautiful. The achiote does two things. It stains the meat a deep terracotta red, and its earthy, faintly peppery flavour anchors the whole dish. The sour orange, which is sharper and more floral than a supermarket orange, tenderises and lifts. The banana leaf traps steam, prevents the pork from drying, and adds a green, tea-like note that no foil ever will. After a night underground the meat pulls apart in wet, spiced strings.

In Mérida and across the Yucatán, cochinita is a Sunday dish. It is served heaped on warm tortillas or stuffed into a torta, topped with cebolla morada encurtida (pickled red onion) and a shard of habanero-based salsa xnipec that will make your eyes water. The acid and the heat are structural, not garnish, and eating cochinita without them is a category error.

Most restaurants today cook it in a covered pot in a conventional oven, and it is excellent that way, but the pib version is still made in villages for weddings, baptisms and Hanal Pixán, the Mayan day of the dead. The difference is real. Wood-smoke and hot earth give the meat a mineral, ferrous depth that no domestic kitchen produces.

On our Mérida tour you'll eat cochinita from a family kitchen that has been running the same recado paste for three generations.

Dan dan mian is a Sichuan noodle dish named after the carrying pole (dan dan) that street hawkers used to shoulder up and down the back alleys of Zilong district in Chengdu in the nineteenth century, with a stove on one end and a bowl of noodles and condiments on the other. It was fast food in the strictest sense, cooked to order on the street, and the dish that emerged is still, at its best, cheap, quick, and unfussy.

The authentic Chengdu original is dry, or nearly so. It is not a soup. In the bottom of a small bowl you have chilli oil, Sichuan peppercorn oil, sesame paste, black vinegar (Baoning cu is the local one, closer to balsamic than to English malt), a little dark soy sauce, minced pickled mustard greens (yá cài, from Yibin), a spoonful of preserved sui mi ya cai, and a scoop of hot pork oil. On top go the noodles, freshly boiled, and a spoonful of dry-fried minced pork with a little more yá cài. The diner tosses the lot at the table, dressing the noodles in the process.

The Americanised and international version, often served in a shallow bath of chilli oil with lots of visible broth, is closer to a Taiwanese adaptation than to the Chengdu original. Both are legitimate but they are different dishes, and if you order dan dan mian in a good hole-in-the-wall in Chengdu you should expect the dry version.

The balance is what matters. Chilli oil, Sichuan peppercorn oil and sesame paste have to sit in equilibrium, none of them shouting over the others. The vinegar is not decoration. It is essential to cutting the sesame and the pork fat, and a dan dan without enough vinegar is heavy and cloying. The peppercorns should be freshly toasted and ground, so the numbing effect is bright rather than dusty.

On our Chengdu tour we take you to a shop in the old Jinli quarter where a woman has been making them the same way since 1978, and where the whole meal, including a bottle of local Snow beer, costs less than a coffee back home.

Dosa is a fermented crepe from south India, made from a batter of raw rice and split urad dal (black gram) soaked overnight, ground to a smooth paste, and then left to ferment for another eight to twelve hours in a warm kitchen until it is airy and faintly sour. Poured onto a hot cast-iron tawa and spread outward in a spiral with the back of a ladle, the batter transforms in seconds into a lace-edged, crackling crepe that is at once crisp on one side and soft on the other.

The fermentation is not optional. It develops the tang that gives the dosa its character, but it also breaks down the raw starch and makes the dish easier to digest. Bacteria and wild yeasts colonise the batter and produce lactic acid and carbon dioxide, which is why a well-fermented batter rises visibly in the bowl and has a slightly sour, sourdough-adjacent smell. This is also why dosa is not really something you can decide to make in the morning for lunch. It is a two-day project.

There are dozens of forms. Plain dosa is just the crepe. Masala dosa, the most famous, has a filling of yellow potato and onion curry rolled into the centre. Paper dosa is stretched extra thin. Rava dosa uses semolina instead of rice, for a lacy, crispier result. Onion uttapam is the thick, pancake-style cousin. Set dosa, Mysore-style, is small and soft. Ghee roast dosa is fried in clarified butter until it is the colour of mahogany. And that is before you get into modern permutations like the sixty-inch family dosa or the chocolate dosa, both of which are more marketing than tradition.

The standard accompaniments are three. Sambar, a thin lentil-and-vegetable stew flavoured with tamarind and asafoetida. Coconut chutney, cool and slightly sweet. Tomato chutney, sharp and spiced. Together they are the reason a plain dosa is never actually eaten plain.

On our Bangalore, Chennai and Kochi tours we take you to a dedicated dosa shop where the tawa is three feet across and the master pours a dosa the size of a small child in under thirty seconds.

Dukkah is an Egyptian dry mix of coarsely pounded nuts, seeds and spices, eaten by dipping bread first into olive oil and then into the dry mix, so the dukkah sticks to the wet bread. It is a beautifully simple idea and one of the great cheap street foods of Cairo and Alexandria. The name comes from the Arabic verb daqqa, to pound or to crush, which is what you do to the ingredients in a mortar.

The composition is not fixed but the framework usually is. You need something nutty, something seedy, something aromatic and something spicy. The most common Egyptian version leans on hazelnuts (roasted and skinned), sesame seeds, coriander seed, cumin, black pepper and salt. Other versions swap in almonds, pistachios, sunflower seeds, chickpeas roasted until crunchy, nigella seeds, dried mint, fennel or a pinch of chilli. What matters is texture. Everything is pounded, not blitzed, so the mix stays coarse and gritty and clings to bread.

The classical method is to dry-toast each element separately (nuts one way, seeds another, spices a third), because they need different heat and timing, and only then to combine them in a mortar and pound the lot with salt. Any home food processor will do a passable job, but a mortar keeps the mix loose. A blender turns dukkah into a paste, which is the wrong texture entirely.

In Cairo dukkah is street breakfast. It is sold in twists of paper by men with wooden trays, alongside a small cup of olive oil and a hunk of hot khubz. In Alexandria and other coastal cities it is often served as an appetiser in restaurants. In the Egyptian diaspora, particularly in Australia, dukkah has been enthusiastically adopted and now turns up sprinkled on roasted carrots, on eggs, on labneh, on burrata, in ways an Egyptian grandmother would find unusual but not unwelcome.

It keeps for a couple of weeks in a sealed jar. After that the oils in the nuts start to oxidise and the mix goes flat. Make small batches often.

On our Cairo tour we take you to a vendor near Khan el-Khalili who has been pounding his own dukkah in the same brass mortar for forty years.

Epazote is a wild herb, Dysphania ambrosioides, with long serrated leaves and a smell that people either adore or find slightly offensive. It grows like a weed across central Mexico, along roadsides, in vacant lots, and on the flat roofs of Mexico City apartments where grandmothers keep a pot for the beans.

The flavour is medicinal, camphorous and green, closest to a mix of oregano, tarragon and creosote. Chewed raw it is almost too much. Simmered into a pot of black beans for the last twenty minutes it becomes essential, adding a resinous top note and, according to every Mexican cook you will ever meet, reducing the gaseous side effects of the beans. The chemistry is real. Epazote contains ascaridole, which does actually act on the gut, and the herb was used pre-Hispanically as an intestinal medicine long before it settled into the kitchen.

Epazote turns up in quesadillas de huitlacoche, in mole verde, in chilaquiles, in green soups, and inside tamales. It does not dry well. The moment you dehydrate it the flavour flattens into something like tea leaves, which is why the dried supermarket version in the west is a poor substitute. If you cannot get fresh, frozen is far closer.

The herb has never really travelled. It is technically edible in North America, where it also grows wild, but nobody outside Mexican kitchens seems to bother with it. That may be because it does not slot easily into other cuisines. Try to use it in a European stew and it fights everything. Use it in a pot of black beans with a hunk of onion and a garlic clove and it is the difference between good beans and beans you remember for a week.

You will spot epazote in every Mexico City market, sold in loose green bundles for a few pesos. On tour we cook a pot of frijoles de la olla with a big sprig thrown in near the end, so you know exactly what it does.

Garam masala is a north Indian spice blend and the name literally means 'warm spices', a reference to Ayurvedic principles that classify certain spices as heat-generating in the body regardless of the temperature at which they are eaten. That is a philosophical framing that pre-dates the recipe by centuries. The mix itself, roughly as we know it today, dates from at least the Mughal courts of the 16th and 17th centuries, when Persian and central Asian cooking techniques met the spice trade of the subcontinent and produced a set of standardised warm-spice blends.

There is no fixed recipe. That is the most important thing to know. A typical northern garam masala might contain cardamom (both green and black), cinnamon, cloves, black pepper, cumin, coriander, nutmeg, mace and bay leaf. A Kashmiri garam masala might drop the coriander and cumin and lean heavily on fennel and dried ginger. A Bengali garam masala might include only three ingredients, cardamom, cinnamon and clove, ground fine and added as a finishing dust. A Gujarati version might include star anise and even rose petals. Every family, and often every generation, has its own balance.

The technique matters as much as the blend. The whole spices are dry-roasted individually on a hot tawa, one at a time, until each releases its oils and darkens by a shade. Only then are they cooled, ground together and stored in a sealed jar. Pre-ground garam masala from a supermarket is a completely different, and much duller, product, because the oils have oxidised long before the powder reaches you.

The correct time to add garam masala is at the end of cooking, not the start. Sprinkled on a finished curry, biryani or daal in the last two minutes, its aromatics stay fresh and bright. Cooked into a base sauce for an hour and it goes flat and dusty. This is the mistake most western home cooks make when they first meet the spice, and it is the reason so many home curries taste like they are missing something.

On our Jaipur and Delhi tours we take you into a spice merchant's shop where the masala is ground to order in front of you.

Ghee is clarified butter that has been taken one step further. Ordinary clarified butter is made by melting butter and skimming the milk solids off the top. Ghee is made by simmering the butter until those milk solids sink to the bottom and toast, turning a deep amber and taking on a nutty, faintly caramelised aroma, and only then is the golden fat strained off the top. That extra step is what gives ghee its particular flavour, and it is why ghee tastes fundamentally richer than French beurre clarifié or middle-eastern samneh, even though the underlying idea is the same.

The other consequence of removing the milk solids is stability. Ghee has essentially no water and no protein left in it. It will keep at room temperature for months without going rancid, which is why it was the standard cooking fat across most of the subcontinent long before refrigeration. It also has a smoke point of around 250°C, well above butter's 175°C, which makes it suitable for the hot-oil frying that Indian cooking demands.

The traditional Indian version is desi ghee, made from cow or buffalo milk, ideally cultured (the cream is soured slightly with yoghurt before churning) which deepens the flavour further. In many rural households ghee is still made in the kitchen from leftover cream, and the toasted milk solids at the bottom of the pan are eaten with rice and salt as a treat for the cook.

Ghee is not a garnish. It is a base ingredient. Almost every serious Indian dish starts with a tablespoon of ghee in a hot pan before the whole spices go in for tadka. Daal, biryani, halwa, kheer, roti brushed straight off the tawa, all of them are carried by ghee. It is also the classical fat of Ayurvedic cooking and of pilgrimage kitchens, where it is considered pure and auspicious in a way vegetable oils are not.

On our Delhi and Jaipur tours we take you into an old halwai shop where the ghee is made fresh in copper pots every morning, and let you taste it warm on a triangle of paratha.

Gochujang is a Korean fermented paste of red chilli, glutinous rice, meju powder (fermented soybean) and salt, aged in earthenware onggi pots for at least six months, and often for years. It is deep brick red, thick enough to hold the shape of a spoon, and it carries a very specific balance of flavours, sweet from the rice starch broken down by the meju enzymes, savoury from the fermented soy, hot but slow-burning from the sun-dried Korean chilli, and salty enough to preserve itself.

The chilli variety matters. Traditional gochujang uses Korean red chillies (gochu) sun-dried and stone-ground into a coarse flake called gochugaru. Korean chillies are unusual, low-medium heat compared to a Thai bird's eye, but with a specific fruity, smoky sweetness that no substitute quite replicates. That is why a gochujang made with Mexican or Chinese chillies always tastes slightly wrong.

The traditional cycle is seasonal. In late winter, women in rural Jeolla and Jeonju used to boil down a jocheong (rice syrup) with meju powder, salt, and chilli powder, pack the paste into a giant onggi pot, seal it with a cloth, and leave it in the sun on the jangdokdae (a raised terrace covered in fermentation jars) for months. Every good Korean home once had one. Today most people buy in a tub, but the artisanal small-batch versions from Sunchang, a town in North Jeolla province famous for its microclimate and its water, are still made this way and are worth seeking out.

In the kitchen gochujang is the base of dozens of sauces. Bibimbap is a spoonful stirred into the rice and vegetables at the table. Tteokbokki is rice cakes simmered in a gochujang-and-anchovy broth. Bulgogi and dak galbi marinades depend on it. Ssamjang, the paste eaten with grilled Korean barbecue and lettuce wraps, is gochujang combined with doenjang (fermented soybean paste), garlic and sesame oil.

On our Seoul tour we visit a specialist shop in Gwangjang market where you can taste half a dozen gochujangs side by side, from six months old to five years.

Huitlacoche is a fungus, Ustilago maydis, that infects ears of corn and causes the kernels to swell into puffy, silver-black galls the size of a walnut. In the United States it is called corn smut and farmers spray to prevent it. In Mexico it is called huitlacoche and farmers pray for it. The good ears fetch a fair price. The infected ears fetch twice as much.

The flavour, once you have it, is unmistakeable. It is earthy and mushroomy but with a specific corny sweetness underneath, somewhere between a truffle and a fresh porcini. The texture, cooked, is inky and slightly gelatinous, like a very fine tapenade. The Aztecs called it cuitlacoch, which some translators render as 'raven's excrement' and others as 'sleeping filth'. Neither translation quite sells it, but the reputation is deserved.

In the kitchen it is always cooked, never raw. The classic preparation is a quick sauté in lard with white onion, epazote and a green serrano, then piled into a quesadilla with a smear of stringy Oaxacan cheese. It is also the filling in crepas de huitlacoche in the fancier Mexico City restaurants, and it makes an extraordinary soup and an even better tamal.

The season is short. Huitlacoche only grows on the ear when the corn plant is stressed, usually by summer rains that hit at the wrong moment, and it must be picked within a few days of the galls forming, before they turn to black spore dust. Fresh season runs roughly July to September in central Mexico. Outside that window you find frozen, tinned or bottled versions, all of which are workable but none of which have the same silky bite as the fresh galls straight off the cob.

On our Mexico City tour we take you to a Sunday market where the huitlacoche vendors stack the galls in wet pyramids and slice you off a hunk to fry, on the spot, into a quesadilla.

Injera is a large, thin, spongy sourdough flatbread made from teff, and it is the foundation of the Ethiopian and Eritrean table. It is served draped over an enormous circular platter called a mesob, with several stews (wat) and vegetable dishes spooned on top of it. Diners tear pieces from a folded stack on the side, use them to pinch up the toppings, and eat everything with their right hand. By the end of the meal the base injera under the stews has soaked up all the sauce and is the best bit.

The grain is teff, Eragrostis tef, an ancient cereal that is barely known outside the Horn of Africa. It is the smallest cereal grain in the world, roughly the size of a poppy seed, and it grows on marginal land in the Ethiopian highlands where wheat and barley struggle. It is also gluten free and unusually rich in protein, calcium and iron. Ethiopian teff comes in three colours (white, red and brown), and the different colours produce injera of noticeably different flavour and appearance.

The making is a two- or three-day project. Teff flour is mixed with water and left to ferment on the counter for 24 to 72 hours, until it is bubbly and sour like a sourdough starter. This fermented batter is then poured in a spiral onto a huge hot clay griddle called a mitad, covered with a lid, and cooked for just a couple of minutes on one side only. The result is a pancake-sized round, pale grey-brown, with hundreds of small holes on the top surface (called eyes) and a smooth, faintly leathery bottom. It is folded, stacked and served cool or at room temperature, never hot.

The taste is startling on first encounter. Sour, faintly beery, cool, with a slightly chewy, spongy texture. It is meant to contrast with the hot, spiced, oily stews on top. The sourness cuts the richness of doro wat (chicken in berbere and butter), the iron of kitfo (chopped raw beef), the depth of shiro (chickpea stew). Without the injera, the stews would be too much. With it, they balance perfectly.

On our Addis Ababa tour we sit around a shared mesob in a traditional restaurant and eat six wats at once, all off the same sheet of injera.

Jollof rice is the great one-pot dish of West Africa, a long-grained rice cooked with a base of blended tomato, red pepper, onion, scotch bonnet chilli, thyme, curry powder and stock, until the grains are separately fluffy, deeply red-orange, and faintly smoky at the bottom from the caramelised layer that forms where the rice meets the pot. It is served at every wedding, every christening, every Sunday lunch across a swathe of West Africa from Senegal to Nigeria, and it is the subject of the single most heated culinary rivalry on the continent.

The name comes from the Wolof people of Senegal, and the historical consensus is that the dish originated somewhere in the old Jolof Empire (roughly modern Senegal, Gambia and Mauritania) in the 14th-16th centuries, as a variation on the local dish thieboudienne. From there it spread east along trade and diaspora routes into Mali, Ghana, Nigeria, Cameroon and Liberia, and each country evolved its own version.

Now for the war. Ghanaian jollof, most commonly made with jasmine rice, uses more tomato paste and less pepper, producing a slightly sweeter, deeper red result, sometimes with the addition of a shito-style spice paste. Nigerian jollof, usually made with long-grain basmati or parboiled rice, uses more scotch bonnet and a specific technique of frying the tomato-pepper base in oil until it has a smoky, caramelised edge, and is traditionally cooked over wood fire for the party-jollof burnt-bottom flavour. Senegalese thieboudienne, arguably the ancestor of both, uses broken rice, a whole fish, and a completely different flavour profile with tamarind and fermented shellfish. Each country insists theirs is definitive. The Jollof Wars are real and extensively documented, with prime ministers and pop stars weighing in.

The party jollof is a specific style. Cooked in enormous cast-iron pots over open wood fires, the very bottom of the rice burns slightly and picks up a smoky, deeply savoury note that home cooking on a gas hob simply cannot reproduce. The crusty burnt-bottom rice is fought over.

On our Accra and Dakar tours we take you to a party-jollof pit where the rice cooks in a pot the size of a bath tub.

Katsuobushi is skipjack tuna that has been simmered, smoked, dried, and then in the highest grades, deliberately colonised with a specific mould, Aspergillus glaucus, before being dried again. The whole process takes between six months and two years and turns a living fish into a piece of what looks like petrified wood. Struck against another piece, katsuobushi rings. In its finished form it is the hardest food product in the world, harder than parmesan by some margin.

That block is then shaved on a kezuriki, a specialised wooden plane with a drawer underneath to catch the flakes. Freshly shaved katsuobushi is almost translucent, a pale pink-brown, and it moves in the air currents above hot food, which is where the trick with dancing bonito flakes on top of takoyaki or okonomiyaki comes from. The heat lifts the flakes and they curl.

The flavour is savouriness in one of its purest forms. Katsuobushi is spectacularly rich in inosinate, the nucleotide that, combined with the glutamate in konbu (kelp), produces synergistic umami many times more intense than either compound alone. That combination is exactly what dashi is: a hot but not boiling water extraction of konbu followed by a brief infusion of katsuobushi. From dashi comes miso soup, most Japanese simmered dishes, most sauces. Nearly everything savoury in Japanese cooking passes through katsuobushi at some point.

The historic centre of production is the town of Makurazaki in Kagoshima prefecture on the south coast of Kyushu, where the fishing fleets have been landing skipjack for at least four hundred years. The full mould-fermented product is called honkarebushi and is expensive enough that most home cooks use the lighter smoked-only version, arabushi, or ready-shaved flakes in sealed bags of hanakatsuo.

On our Tokyo and Kyoto tours we visit an old katsuobushi shop where the master shaves a block by hand and hands you a translucent curl of flake to eat directly, so you understand what dashi actually starts from.

Khao soi is a noodle soup from the north of Thailand, closely related to the Burmese ohn no khao swè and to a family of coconut-curry noodle dishes that stretch from Yunnan through Shan State into Laos and northern Thailand. It arrived in Chiang Mai, most food historians agree, via the Chin Haw, Muslim Yunnanese traders who moved down the caravan routes in the nineteenth century.

The bowl is a masterclass in contrast. Underneath is a broth of coconut milk enriched with a rich yellow curry paste (turmeric, coriander seed, cardamom, ginger, shallot, dried chilli, curry powder) and a fatty piece of chicken on the bone or a chunk of braised beef. On top, in the same broth, sits a nest of soft egg noodles. Piled over both is a wad of the same noodles fried until brittle and coppery. On the side, always, come four garnishes: sliced shallot, mustard greens pickled sharp with vinegar and salt, chilli oil (nam prik pao), and a wedge of lime. You are meant to add all four to your bowl.

The pleasure is textural as much as it is flavour. The soft noodles carry the broth, the crisp noodles snap and then dissolve, the pickled greens cut through the coconut, and the chilli oil floats on top in orange lakes. Every mouthful is a slightly different combination.

Chiang Mai is the epicentre. The old Muslim quarter around Charoen Prathet Road has the classic shops, several of them run by the same families for four or five generations. Khao Soi Khun Yai, Khao Soi Nimman and Khao Soi Islam are three names that come up in every serious guide, and all three deserve the reputation. Prices are absurd. A large bowl runs 60 to 80 baht, roughly the price of a cup of coffee in London.

On our Chiang Mai tour we start you at a khao soi shop that has been on the same corner since 1948, and let you assemble the condiments to your own taste.

Kimchi is not one thing. It is a category. There are, by conservative count, more than 180 documented types, and probably many more informal family versions. What unites them is a process, not an ingredient. Vegetables are salted to draw out water and to give lactic acid bacteria the environment they need, then dressed with seasoning and packed into a jar to ferment. The rest is regional preference and household inheritance.

The most famous version, and the one non-Koreans usually mean when they say kimchi, is baechu kimchi, whole-cabbage kimchi. Napa cabbage is quartered, salted for a few hours, rinsed, then coated in a red paste of gochugaru (Korean chilli flake), garlic, ginger, spring onion, salted shrimp (saeu-jeot) or fish sauce, sometimes a spoonful of rice-flour porridge for body, and sometimes julienned Korean pear or apple for sweetness. Packed into a jar it ferments for a few days at room temperature before going into the fridge, where it will keep improving for months.

Other regulars include kkakdugi, cubed radish kimchi, crunchy and sweet; oi sobagi, cucumber stuffed with chive and chilli, best in summer; nabak kimchi, a mild, watery, pink kimchi eaten as a cold soup; and baek kimchi, white kimchi without chilli, for children and for people who cannot stomach the heat.

The great annual event is kimjang, the communal autumn kimchi-making that historically ensured a family had enough fermented vegetable to see them through the winter. Women (traditionally, though this is loosening) would gather in November, salt hundreds of cabbages, and pack the finished kimchi into buried onggi pots to control the fermentation. Kimjang is now on the UNESCO intangible cultural heritage list, which was overdue.

Old kimchi, kimchi that has fermented for six months or more, is prized. It is too sour to eat as banchan, but it is exactly what you want for kimchi jjigae (a stew), kimchi bokkeumbap (fried rice) and kimchi jeon (a pancake).

On our Seoul tour we visit a kimchi cellar in the older quarter and eat six versions in a row, so you understand it is a family, not a jar of shop-bought paste.

Kōji is a mould, Aspergillus oryzae, deliberately cultivated on cooked grain, usually rice or barley, and then used as the starter for the entire family of Japanese fermented seasonings. It has been designated the national fungus of Japan by the country's own brewers association, which is not something many countries do for a mould, and the designation is deserved. Without kōji there is no sake, no soy sauce, no miso, no mirin, no rice vinegar, no shochu.

Physically the mould looks like a fine dusting of white or greenish fuzz on the rice, and it smells sweet and slightly floral, somewhere between fresh chestnut and cooked jasmine rice. The magic is enzymatic. Kōji produces two families of enzymes in industrial quantities. Amylases break down starches into fermentable sugars. Proteases break down proteins into free amino acids, in particular glutamate, the amino acid that tastes of umami. That double action is why any food touched by kōji becomes both sweeter and more savoury at the same time.

In the traditional workflow, spores are sprinkled on cooled steamed rice, laid out in shallow cedar trays, and incubated for two to three days in a temperature-controlled room called a muro. Once fully grown, this rice kōji is either used fresh (as the starter for sake), mixed with cooked soybeans and salt to make miso, or mixed with soybeans and wheat to make soy sauce (shoyu).

Two direct kōji seasonings, shio kōji (salt kōji) and shoyu kōji (soy kōji), have exploded in popularity in the last twenty years, partly through the writing of chefs like Nancy Singleton Hachisu. Rub a chicken breast with two teaspoons of shio kōji, leave it overnight in the fridge, wipe it off and grill it. The result is tenderised, sweetly savoury, subtly more flavourful than the same chicken with just salt.

On our Kyoto tour we visit an old miso brewery where you can walk through the muro and see the trays of pale kōji-covered rice warm to the touch, alive with the mould that quietly built Japanese cuisine.

Larb, also spelt laab, laap and larp, is the national dish of Laos and the defining dish of northern and northeastern Thailand. Etymologically the word is thought to derive from an old Lao term meaning good fortune, which is why larb is served at weddings, housewarmings and Lao new year. It is also, as it happens, one of the great five-minute dishes of the world.

The base is minced meat, usually chicken, pork, duck, beef or fish, cooked briefly in a hot dry pan with a splash of stock or water rather than oil, so that the meat stays loose and grainy rather than caking together. Off the heat, it is dressed with fish sauce, lime juice, dried chilli powder, chopped shallot, spring onion, mint, saw-leaf coriander and, crucially, khao khua, a coarse powder of raw sticky rice toasted in a dry pan until deep amber, then pounded in a mortar. The khao khua is what gives larb its particular nutty crunch and its ability to hold the dressing.

Larb Lao, the original, is often served warm or at room temperature and, in Luang Prabang and Vientiane, sometimes with raw meat and blood, larb dip, in the same way steak tartare is served in Europe. Northern Thai larb, from Chiang Mai and Chiang Rai, is larb muang, seasoned with a dry spice blend of cumin, clove, star anise, cassia and mahlab, which gives it a much more perfumed depth than the Isaan or Lao versions. Isaan larb is closer to the Lao original, sharp with lime and hot with dried chilli.

The correct way to eat it is by hand, with sticky rice pinched into a ball and used as a spoon, and with a plate of raw vegetables on the side (long beans, cabbage wedges, cucumber, mint stalks) that you use to freshen the palate between bites. Cold beer helps.

On our Chiang Mai tour we take you to a family kitchen where the cook toasts the khao khua on a wood-fired stove, five minutes before the larb hits the plate.

Málà is not a spice. It is a sensation, produced by the deliberate combination of two ingredients, huajiao (Sichuan peppercorn) and hot dried chilli. The word breaks down neatly. Má, numbing, describes the tingling anaesthetic buzz of the peppercorn. Là, spicy hot, describes the burn of the chilli. Together they produce a paradoxical sensation, part cold prickle, part hot burn, that fires two entirely separate nerve pathways at once. The mouth cannot decide what it is feeling and stays interested.

The huajiao is worth its own paragraph. It is not related to black pepper or to any chilli. It is the husk of a small berry from Zanthoxylum trees, and it contains a molecule called hydroxy-alpha-sanshool that binds to touch receptors in the mouth and causes them to fire at a frequency of around 50Hz. The physical effect is the same as putting a small vibrating device on your tongue. Good fresh huajiao from Sichuan (particularly the red variety from Hanyuan county, which is prized) has a strong citrus-floral perfume alongside the numbing effect, closer to grapefruit peel than to any peppercorn a European would recognise.

The chillies are usually dried erjingtiao or Chao Tian Jiao, and they are added in enormous visible quantities, more to perfume the oil than to be eaten. The rule of thumb in a proper Chengdu hotpot restaurant is that you fish around in the broth for the pieces of meat and vegetable, ignore the drift of chillies, and never actually swallow one whole.

Málà is the defining flavour of Sichuan and Chongqing cooking, but it now stretches across China and beyond. It is the base of mapo tofu, of dan dan noodles, of Chongqing chicken, of the entire Sichuan hotpot tradition, and, in a shift that the last decade has confirmed, of pretty much every trendy new restaurant opening from Beijing to Shanghai to London.

On our Chengdu tour we start you with a mild mápó dòufu, then work you up over a few days to a full hotpot with jade-red oil, and by the end you are ordering huajiao by name.

Masa is nixtamalised corn, ground wet, and turned into a soft dough. It is not flour and water. It is not polenta. It is a living, slightly tacky, faintly sweet paste that smells of hot stone and toasted corn, and it is the foundation of half of Mexican cooking.

The corn is simmered with cal (calcium hydroxide) the day before, drained, rinsed, and then ground on a stone metate or fed through a molino. What comes out is masa. Left plain, it holds together for maybe eight hours before it starts to sour, which is why serious tortillerías grind fresh every morning. That short shelf life is also why a real corn tortilla tastes nothing like the shrink-wrapped version sold in supermarkets in Europe or the United States.

Masa is not one thing. There is masa fina, ground twice, silky, used for tortillas. There is masa quebrada, coarser, for tamales, where you want a bit of grit to hold the fat and the filling. There is masa preparada, already seasoned with lard and salt, sold in bags by the kilo to home cooks who don't own a molino. And there is masa harina, the dried-and-milled shortcut, invented by Maseca in the 1940s, that lets you make an approximation of masa anywhere in the world by adding hot water.

From masa comes tortillas, tamales, sopes, huaraches, gorditas, tlacoyos, chalupas, memelas, panuchos, salbutes, tetelas, molotes, tostadas. Colour it blue with heirloom maíz azul. Colour it black with huitlacoche. Sweeten it and steam it in banana leaf. Fry it, griddle it, boil it in broth. The dough itself is neutral scaffolding, and every region builds a different building on top.

You will smell fresh masa before you see it, on any Mexican street where a tortillería is grinding. That corn-and-lime perfume is the single most reliable marker of the country's cooking, and once you know it, you can find breakfast anywhere. On a Mexico City morning we take you to a working tortillería at dawn, so you can watch the nixtamal come off the mill and press your first tortilla by hand.

Mirin is a sweet rice wine used almost exclusively for cooking. The traditional version, honmirin, is made by fermenting steamed glutinous rice with koji and shochu for between one and three months. The koji enzymes break down the starch of the rice into sugars, and the alcohol from the shochu stops the fermentation before yeasts can convert those sugars into more alcohol. What you are left with is a syrupy amber liquid at about 14% alcohol and roughly 40% sugar, with a deep, mellow, slightly caramelised sweetness and a faint hit of the underlying rice wine.

Mirin has three jobs in the kitchen. It sweetens, but with much more complexity than sugar. It glazes, because when it hits a hot pan the sugars caramelise and coat the food in a shiny lacquer, which is why teriyaki chicken and yakitori come out with that particular shimmer. And it tenderises fish and meat, because the alcohol denatures the surface proteins and helps a marinade get in. It also, quietly, does a fourth thing, which is masking. A splash of mirin in a broth softens sharp edges from soy sauce, vinegar or miso, and pulls a sauce into balance.

You need to know the categories. Honmirin is the real thing, sold in glass, taxed as an alcoholic beverage, and the only grade that will give you the proper flavour and glaze. Mirin-fu chomiryo, sometimes labelled as mirin-style seasoning, is fake mirin, just corn syrup and MSG with a splash of ethanol added later, and it is what you find in most Western supermarkets. Shio-mirin is salted mirin, a legal workaround in Japan that lets shops sell it without an alcohol license because the salt makes it undrinkable. Any of the three will function in a recipe, but only honmirin will give you the depth.

In classic sauces, mirin is combined with soy sauce and sake in fixed ratios. Teriyaki is typically 1:1:1 sugar-soy-mirin. Tsuyu, the base for soba dipping sauce, is 1:1:4 mirin-soy-dashi.

On our Kyoto tour we visit a small brewery that has been making honmirin the same way since the 1860s.

Nước mắm is Vietnamese fish sauce, and the best of it comes from the island of Phú Quốc in the Gulf of Thailand, where the particular species of anchovy (cá cơm) and the exceptionally salty water conspire to make something that is legally protected in the same way champagne is. The process is medieval. Whole small anchovies are layered with sea salt at a ratio of roughly three to one, packed into wooden vats that hold twelve tonnes at a time, and left in the sun for between twelve and eighteen months. What drips out of the tap at the bottom of the vat is the first-press liquid, called nước mắm nhỉ, which is expensive and used raw. What is drawn from the middle and the second press is standard-grade cooking sauce.

The flavour of a good nước mắm is not the aggressive, chemical stink of the cheap supermarket bottle. It is round, savoury, faintly sweet from the natural fermentation, and it hits the back of the tongue with the same umami wallop as a very expensive parmesan. It is not a garnish. It is a base seasoning, the way soy sauce is in Japanese cooking or salt is in French cooking, and there is almost no Vietnamese savoury dish that does not use it at some stage.

In the kitchen it is used in two ways. Straight, mixed into marinades, stir-fries, braises and broths, where it dissolves and disappears into savouriness. Or, more famously, as the base of nước chấm, the dipping sauce found on every Vietnamese table. Nước chấm is nước mắm cut with lime juice, sugar, water, garlic and bird's-eye chilli, and every family has a slightly different balance.

Old bottles darken from clear amber to mahogany. They do not go off. A good Phú Quốc nước mắm from a decade ago is still perfectly usable, just more concentrated.

On our Hanoi and Ho Chi Minh City tours we crack open a bottle of first-press nước mắm at a family kitchen so you can taste it spoon-to-mouth, which is the only way to understand what people mean when they call it Vietnamese wine.

Phở is a beef noodle soup from the Red River delta of northern Vietnam, and although it now feels ancient it is not. The dish as we recognise it dates from the very late 1800s or early 1900s, born somewhere between the French colonial appetite for beef and the older Vietnamese habit of noodle soups. The word phở is thought by many food historians to be a Vietnamese pronunciation of the French pot-au-feu, though the etymology is still argued. What is not argued is that it started in the north and only migrated south with the great population movement of 1954.

The two families are phở bắc (northern) and phở nam (southern). Northern phở is clear, austere, restrained. The broth is beef bones and oxtail simmered for eight hours or more with charred ginger and shallot, star anise, cinnamon, cassia, cardamom and clove. The seasoning is fish sauce and rock sugar, nothing more. On the table you get a lime wedge and some sliced chilli, and that is it. Southern phở is sweeter and busier, with hoisin and sriracha on the table and a mountain of Thai basil, saw-leaf herb, bean sprouts and lime piled next to the bowl.

The noodles are bánh phở, flat rice noodles about half a centimetre wide, blanched to order. The beef options run through tái (rare eye of round, sliced paper thin and cooked by the hot broth), chín (well-done brisket), nạm (flank), gầu (fatty brisket), gân (tendon) and viên (meatballs). The purist orders phở tái nạm gầu, which gives you three textures in one bowl.

A good phở broth is judged by clarity and by depth. It should look like weak tea and taste like a concentrated bone broth with the spices on the exhale, never up front. If the broth is cloudy the bones were boiled too fast. If the spices are shouting, someone was heavy-handed with the star anise.

On our Hanoi tour we take you to a shop that has been running the same broth pot for forty years, and you eat it standing at a plastic stool at 7am, the way locals do.

Prahok is a Cambodian fermented fish paste with a smell that will empty a room and a flavour that anchors an entire cuisine. It is often called Cambodian cheese, both because of the pungency and because of the role it plays. You would not eat it neat any more than you would spoon Roquefort out of a jar, but it is in almost everything.

The traditional production runs on the annual flood cycle of the Tonlé Sap, the great inland lake that swells and shrinks with the monsoon. When the waters recede in late November and December, small freshwater fish (particularly trey riel, the Mekong carp that gives the Cambodian currency its name) are caught in immense numbers, more than can be eaten fresh. The surplus is cleaned, salted, packed into earthenware jars, weighted with stones and left to ferment for anything from three months to three years.

The result is a grey-brown paste with visible fish bones and a smell somewhere between mature blue cheese, low tide and a very old wardrobe. Fear it at your peril. That funk is savouriness in concentrated form. A small spoon of prahok stirred into a coconut-based amok, a lemongrass soup or a fresh raw-vegetable dipping sauce (prahok ktis) transforms it from pleasant to definitively Cambodian.

The dish that reveals it best is prahok ktis. Minced pork is fried with lemongrass, kaffir lime leaf, garlic and a couple of tablespoons of prahok, then loosened with coconut milk into a rough dip that is served with a plate of raw cucumber, aubergine, long beans, cabbage and unripe mango. You scoop the hot dip onto the cold vegetables and eat with rice.

Neighbouring cuisines have their own versions of the same technique. Thai pla ra, Lao padaek and Vietnamese mắm are all cousins, and once you have tasted one you understand the whole family.

On our Phnom Penh tour we visit the fish markets and open a small jar of prahok in a kitchen that has been making it since the 1970s, when the family fled the Khmer Rouge and came back to their village.

Ras el hanout is a Moroccan spice blend and the name translates roughly as 'head of the shop', which means the top-shelf, best-of-the-house mix that a spice merchant offers as a signature. It is not a fixed recipe. It is a boast. Every attar (spice merchant) in the souks of Marrakech, Fes or Casablanca has his own version, jealously guarded, and the number of ingredients ranges from a modest fifteen to well over forty.

The core is usually there. Cumin, coriander, cinnamon, ginger, black pepper, cardamom, nutmeg, mace, cloves, allspice, turmeric, chilli and paprika. The showpiece additions are what separate a plain shop from a serious one. Dried rosebuds, orris root, grains of paradise, cubeb, long pepper, monk's pepper, ash berries, galangal, fenugreek, saffron and, in some of the older mixes, cantharides beetle (Spanish fly), which is now illegal for obvious reasons but was once a marker of very expensive ras el hanout aimed at newlyweds.

The flavour is warm, sweet, deep and floral all at once, quite unlike the more directly savoury Indian garam masalas or the sharp Levantine baharat. That floral quality is the rose and the orris root, and it is what makes ras el hanout so recognisable in a tagine or a couscous. A pinch is enough. Too much and the sweetness of the mix starts to dominate and the dish tips out of balance.

In the Moroccan kitchen ras el hanout goes into slow-cooked lamb and chicken tagines, into the broth for mrouzia (a wedding lamb dish sweetened with honey and raisins), into the stuffing for a whole pigeon in bastilla, and rubbed onto kefta before grilling. It is added at the start of the cook, not the end, because it needs the long simmer to melt into the sauce.

On our Marrakech and Fes tours we take you into the souk el attarine, the spice quarter, and stand you in front of a merchant who has been blending his own ras el hanout for thirty years, so you can smell each of the twenty-eight ingredients before he mixes them in front of you.

Som tam is a green papaya salad and it is the single most popular street dish in Thailand. It comes from Isaan, the northeastern region that shares a border and much of its food culture with Laos, where the near-identical dish is called tam mak hoong. The name som tam literally means 'sour pounded', which is what happens to it in the tall clay mortar (khrok din) that every vendor swings a heavy wooden pestle over.

The recipe, roughly, is this. Into the mortar go raw garlic, a heap of bird's-eye chillies, palm sugar and a splash of lime juice. You pound to a paste. Then long beans, cherry tomatoes, dried shrimp, roasted peanuts, and finally the star, ribbons of unripe green papaya, shredded with a hand-held cleaver against the whole fruit. The lot is bruised, not smashed, so the papaya keeps its crunch. Fish sauce goes in near the end, sometimes joined by tamarind paste and, in the more fearsome versions, salted crab or fermented anchovy paste.

The five tastes are all supposed to be present at once. Sour from the lime, sweet from the palm sugar, salty from the fish sauce, spicy from the chillies, and umami from the dried shrimp. A properly balanced som tam has none of them dominant. A single dish can carry ten chillies without shouting, because the sugar and the acid frame the heat.

The Isaan version, som tam pu pla ra, is the pungent one, with fermented fish sauce and salted crab, and it is not something to order on your first day in Bangkok. Som tam Thai, the milder Bangkok version with peanuts and dried shrimp, is what most tourists meet first. Som tam poo, with soft-shell salted blue crab, is the sweet spot.

It is eaten with sticky rice pinched into a ball by hand, and with grilled chicken (gai yang) on the side. On our Chiang Mai and Bangkok tours we watch the vendor pound your bowl to your specified spice level, then eat it standing at the cart.

Tadka, also called tarka, chhonk, baghar, phoron, thaalippu and half a dozen other names depending on which language you are cooking in, is the technique of frying whole spices in a small amount of hot fat and then adding either the hot spice-fat mixture to a finished dish or the raw ingredients to the tempered fat as the base for a curry. It sounds trivial, and it is one of the single most important techniques in the Indian kitchen.

The chemistry is straightforward. Most of the aromatic compounds in whole spices (cumin, mustard seed, fenugreek, nigella, curry leaf, dried red chilli) are fat-soluble, not water-soluble. Frying them in hot ghee or oil for thirty seconds extracts those compounds, transforming them from muted background notes into loud, aromatic, present flavour, and infusing the fat itself. Water cannot do this. Neither can dry roasting for very long. The window is small and the difference is night and day.

A daal without tadka is a bowl of cooked lentils. The same daal with a tadka of cumin, mustard, curry leaf, dried chilli and asafoetida poured sizzling on top thirty seconds before serving is a completely different dish. In some households, tadka is poured at the table, so the dining room fills with the sudden warm scent of blooming cumin as the diner walks in.

The technique varies regionally. Bengali panch phoron uses five whole spices (nigella, fenugreek, cumin, black mustard, fennel) in equal parts. Tamil thaalippu almost always includes curry leaf and mustard seed in coconut oil. Punjabi tadka leans on cumin, garlic and dried red chilli in ghee. Gujarati vagharoo often adds hing (asafoetida) and sesame. Kashmiri Pandit cooking uses a tadka of hing and dry ginger in ghee, no onion or garlic, and gets extraordinary depth from it.

On our Delhi, Jaipur and Mumbai tours we cook a daal from scratch in a family kitchen so you can see the tadka poured on at the end and understand what the technique actually does to a bowl of food.

Tagine is two things at once, and the confusion is intentional. It is the conical clay vessel, and it is the dish cooked inside it. In Morocco you will hear both usages daily and no one is bothered by the double meaning.

The pot itself is a triumph of low-tech engineering. A shallow, round earthenware base holds the food. A tall conical lid sits over it. When the pot is placed on a low heat, usually a bed of glowing charcoal, the moisture from the food rises into the cool cone, condenses on the inner walls, runs back down the sloped sides, and drips onto the food again. The cook adds almost no water. What comes out is a stew that has essentially braised in its own juices and evaporated flavour compounds, concentrated rather than diluted.

The classics are worth knowing. Tagine of lamb with prunes and almonds, sweetened with honey and cinnamon and often finished with toasted sesame. Tagine of chicken with preserved lemon and green olives, sharp and salty and one of the great Moroccan dishes. Kefta mkaouara, meatball tagine with tomato and eggs cracked in at the end. Berber tagine, which is really a mixed vegetable and meat stew, piled in a tall cone in the pot before the lid goes on, so the vegetables steam over the meat. Fish tagine on the coast, with chermoula and preserved lemon. Tagine of quince, of dates, of pears, of every fruit in season.

The clay is critical. The good pots are unglazed on the outside and only partially glazed on the inside, so they can absorb smoke from the charcoal and impart a specific earthy note to the food. The famous pots from Salé and Fes are heavier and unpainted, meant for cooking. The pretty coloured pots from Marrakech markets are decorative and will crack on real heat.

The tagine also functions as its own serving dish. It is placed in the middle of the table, the cone is lifted with a flourish, and everyone eats directly from it with pieces of khubz bread, no cutlery. On our Marrakech and Fes tours we cook a full tagine with a family, on charcoal, and eat it directly from the pot.

A thali is a round metal platter, usually steel or brass, on which a full Indian meal is served in a set of small matching bowls called katoris. It is one of the most efficient serving formats ever devised. In one glance you see the whole meal, in balanced proportion, and you eat it in whatever order and rhythm you like. The word thali just means 'plate'. The dish takes its name from the vessel.

The philosophy is old. Ayurvedic and Tamil dietary tradition holds that a proper meal should contain all six rasas, or tastes: sweet, sour, salty, bitter, pungent and astringent. A well-composed thali is built to deliver all six, in the right amounts, with the right textures and temperatures. Something wet and something dry. Something hot and something cool. Something spicy and something soothing. Something soft and something crunchy. The eater is the composer, mixing and matching bite by bite.

A Gujarati thali is famously sweet and vast, running to twenty small dishes with kadhi, dal, three or four vegetable sabzis, several pickles, farsan, dhokla, roti, rice, papad, chutneys, mango ras in season, and shrikhand for dessert. A Rajasthani thali is drier and spicier, built around dal-baati-churma. A South Indian meal, served on a banana leaf rather than a metal platter, follows the same logic but with sambar, rasam, coconut chutney, sabzis, curd rice and payasam. A Bengali thali starts with something bitter, moves through fish and vegetables, and finishes with dessert, in a prescribed order.

The commercial thali, particularly the unlimited (unlimited-refill) thali common across Gujarat and Maharashtra, is a modern wonder. For a few hundred rupees you get an endless stream of servers with buckets, refilling anything on your plate the moment you make a dent in it. Eating one properly requires strategy, pacing, and the discipline to say no when the third round of ghee arrives.

On our Jodhpur and Ahmedabad-adjacent tours we take you to a family-run thali house where the meal comes out in twenty small bowls and the entire ritual takes a leisurely two hours.

Wok hei is a Cantonese term, literally 'breath of the wok', and it refers to the specific savoury, faintly smoky, almost caramelised flavour that a properly seasoned carbon-steel wok imparts to food when it is hot enough. It is one of the hardest things in cooking to produce and one of the easiest to recognise. Once you have eaten a plate of true wok-hei beef chow fun, you spend the rest of your life comparing every stir-fry to it and being mildly disappointed.

The chemistry involves three overlapping processes. Aerosolisation of oil on the wok's surface, which creates a fine spray of hot droplets that partially combust. Maillard browning of proteins on food surfaces at very high temperatures, well over 200°C. And the deliberate ignition of stray oil at the pan's edge, which produces short bursts of flame that lick the ingredients as they are tossed. The flavour compounds produced include pyrazines and other roasty-smoky molecules that domestic hobs simply cannot generate.

The equipment is non-negotiable. You need a well-seasoned carbon-steel wok with a rounded base, sitting on a jet-engine burner (twenty times more powerful than a domestic gas hob), with the ingredients cut small enough to cook in under a minute. You need a wok chan (a long-handled shovel-like spatula) and a wok jong (a wire scoop for lifting food out fast). You need to be flipping and tossing constantly, so food touches the metal only in flashes, never long enough to steam.

This is why the classic dishes of wok hei (beef chow fun, yeung chow fried rice, singapore mei fun, garlic pea shoots) taste fundamentally different at a good Cantonese cha chaan teng or dai pai dong than they do at home. The home version is a stir-fried facsimile. The restaurant version has a specific, almost incense-like smoke that no home cook can quite reproduce without the equipment.

On our Hong Kong tour we take you into a dai pai dong at midnight, where the wok chef holds the handle in one hand and a two-litre kettle of stock in the other, and you can watch the flames leap out of the wok in six-inch tongues as he tosses a plate of pea shoots into wok hei perfection.

Xiao long bao are small, pleated, soup-filled dumplings from the Jiangnan region of eastern China, specifically from Nanxiang, a town now absorbed into greater Shanghai. The name literally means 'small basket bun', a reference to the little bamboo steamers they are served in, and the dish is thought to have been created in the 1870s at Gu Yi Yuan restaurant in Nanxiang, which somehow still exists today.

The trick that makes them extraordinary is the soup inside. The filling is not liquid when it goes into the dumpling. It is a cold mixture of minced pork and diced aspic, a stiff gelatinous jelly made by slow-simmering pork skin, bones and sometimes chicken feet, then chilling the resulting broth until it sets solid. Cut into cubes, the aspic gets folded into the meat mixture. When the dumpling is steamed, the aspic melts back into liquid, and you end up with a dumpling full of hot soup.

The wrapper is not the same as a jiaozi wrapper. It is thinner, made with hot water dough, rolled paper-thin at the edges and left slightly thicker at the centre so it can bear the weight of the filling without splitting when picked up. A properly made xiao long bao has between 14 and 18 pleats gathered into a neat topknot. That number is not decorative. Fewer pleats and the dumpling breaks. More and the top becomes too thick to swallow.

The correct way to eat them is choreographed. Lift the dumpling gently with chopsticks by the topknot, set it on the ceramic spoon, nip a small hole in one side to let the steam escape, sip out the soup, then eat the wrapper and pork. Skip any of these steps and you either burn your mouth or lose the soup on your shirt. A splash of dark Chinese vinegar (Zhenjiang black vinegar) and a shred of ginger go on the spoon before the dumpling.

On our Shanghai tour we take you to a family-run xiao long bao shop in the old French Concession where the wrappers are hand-rolled to order and the aspic is made fresh every morning.

Za'atar is two things at once, again. It is a wild herb, closely related to oregano and thyme (specifically Origanum syriacum, the Syrian oregano or Bible hyssop), that grows on the hillsides of Palestine, Lebanon, Syria and Jordan. And it is a spice blend built around that dried herb, together with toasted sesame seeds, sumac, salt, and sometimes cumin, dried marjoram or coriander seed.

The blend varies by country and, more granularly, by village. Palestinian za'atar leans heavily on the wild herb and uses less sumac. Lebanese za'atar is greener and slightly more herby. Jordanian za'atar sometimes adds ground caraway. Syrian za'atar can include dried mint. There is no consumer-side standard, and buying za'atar in a spice shop in Amman, Jerusalem or Beirut is a small education. Ask to try three, they will taste noticeably different, and you will start to develop preferences.

The everyday use is manoushe, a Lebanese flatbread topped with a paste of za'atar mixed into olive oil and baked in a hot oven until the edges char. It is the standard Lebanese breakfast, sold from street ovens from six in the morning, wrapped in paper and eaten walking to work. In Palestine and Jordan, za'atar is scattered on top of labneh (strained yoghurt) with a lake of olive oil, and scooped up with warm khubz. In Israeli kitchens it turns up on roasted vegetables, on chicken thighs, on hard-boiled eggs.

There is a saying in the Levant that za'atar sharpens the mind, and Palestinian schoolchildren are traditionally given a wrap of flatbread, olive oil and za'atar before exams. Whether or not the folk wisdom holds, the combination of the herb's essential oils, the toasted nuttiness of the sesame, and the fruity sourness of the sumac produces a flavour that is deeply satisfying and specifically Levantine. Nothing in western cooking quite matches it.

On our Jerusalem and Amman tours we start you with a hot manoushe from a wood-fired oven, and buy you a bag of proper Palestinian za'atar to take home.