Hot licks

"Flavour, flavour, flavour" is the cri de coeur of every chef in search of the perfect dish. Every ingredient is assessed - how to maximise this element and negate that? Every chef employs a whole armoury of techniques to achieve this, including their own personal battery of seasonings. The chilli is as essential to this list as black pepper, salt or lemon.

Chillies are part of the capsicum species and belong to the solanaceae family. In other words, sweet peppers are a very mild relation of the ultra-hot habañeros. They all originated from Central and South America, where they have been eaten since at least 7000BC. Cultivation occurred later - around 5000 to 3000BC.

It was not until Columbus brought his first plants back to Europe in 1492 that chillies spread to Africa and Asia. There are now thousands of varieties, and even botanists have trouble classifying them all. There are as many flavours and degrees of heat as there are varieties, and these can be altered by drying, smoking and roasting -glorious for any chef with an adventurous spirit.

The heat in chillies comes from a chemical called capsaicin, 80% of which is found in the white ribs and seeds. These should be removed for milder dishes. Capsaicin can burn the skin, so if you plan to handle a lot of chillies or have sensitive skin, you must wear rubber gloves.

Taste of happiness

Australian research has shown that capsaicin has the effect of intensifying certain flavours. There is also evidence that it promotes the production of endorphins, the body's natural pain-killers that stimulate a sense of pleasure and wellbeing. Perhaps this is why people become so addicted to eating them.

The heat of chillies has been classified in "Scoville Heat Units". Chillies can range from zero to 300,000 units, so it's a useful reference if you don't want to burn your tongue before breakfast.

As a growing number of varieties becomes available, chefs need to learn about their comparative flavours and heat levels. It is worth buying a few and comparing them. Jalepeños, for example, have a fresh, green flavour with a clean heat, whereas habañeros have a delicate fruitiness mixed with a peppery heat. Anaheim chillies are very mild and have a slightly metallic taste, like green peppers.

Susan Spicer, chef and joint owner of Bayona in New Orleans (who recently visited the Lanesborough in London), believes you should try to find out how each type of chilli is used in its indigenous culture. "My style of cooking is very eclectic and although I really like spicy food, I try not to overdo it on my menu," she says.

Surprisingly, despite working in the heartland of Cajun cooking, her dishes are very mild by British standards. "I like to use fresh Jalepeños, serranos, Scotch bonnets, Thai chillies and poblano chillies. I use a lot of dried cascabels, anchos, de arbols and chipotles as well as the usual chilli pastes, chilli sauces and harissa."

Spicer's richly flavoured gumbo takes its tickly heat from the spicy tasso and a dash of indigenous Tabasco, while grilled shrimp (prawns) are served with black bean cakes and a delicate coriander and jalapeño sauce. Caribbean Scotch bonnets are added to mango salsas, along with a pinch of allspice, lime and orange juice. Dried US chillies, such as sweet, fruity anchos and mild guajillos, are lightly roasted, soaked and blended together with molasses and home-smoked onions, tomatoes and garlic to create a luscious barbecue sauce for grilled pork chops.

Das Sreedharan, chef-owner of the recently opened Rasa W1 in London, would never dream of using anything but Indian chillies in his Kerala vegetarian food. "I buy them direct from India or from AK Singh & Co in the new Spitalfields market," he says. Despite restricting himself to chilli powder, dried north Indian red chillies and the long, fresh green chillies of southern India, he manages to create subtle layers of complex heat mixed with freshness. A mixture of vegetables might be cooked in tamarind water with a hint of turmeric and chilli powder before being seasoned with roasted and ground coriander seeds, red chilli and coconut. Black mustard seeds are fried briefly with curry leaves and red chillies, then tipped, with the oil, into the curry.

"Southern Indian cooking is very fresh and creative," explains Sreedharan. "We care about the colour as well as the taste. We don't use chilli to make things hot, but as an essential ingredient, along with ginger, tamarind and curry leaves. They are added to most curries, but in different proportions and in different ways." Green chilli adds a certain zingy freshness, while roasting red chillies will draw out their aromatic nature.

Each chef has their own approach to chillies. Rosemary Ray, chef-manager at Maud's Tea Rooms at Maud Foster Mill, Boston, Lincolnshire, cooks only vegetarian food, preferably with organic ingredients, alongside the incredible flours the windmill grinds. "I find chillies help to give body to dishes, whether it is a hearty chickpea stew or a sweet corn fritter served with a spicy tomato chutney," she says. Ray makes her own green and red Thai-style curry pastes, as well as countless different pickles and chutneys.

Daniel McDowell, executive chef at Dakota in London, is fascinated by the diversity of dried chillies and draws on his experience from travelling around South America and Asia. He buys his dried chillies from the Cool Chilli Company (see panel above) and is continually evolving new recipes.

The smoky flavour of pasilla de Oaxaca (smoked pasillas) is transformed into an unctuous chilli jam with sautéd onion, garlic, tomatoes, vinegar and soy sauce before being served with pan-fried soft-shell crab. Home-smoked rabbit is gently braised with mild dried guajillo chillies (which taste like green tea) and a vegetable mirepoix before being shredded and wrapped with some of its sauce in tortillas, topped with Monterey Jack cheese and baked, then served with a lemon fig salsa.

McDowell, an admitted chilli fanatic, is constantly striving to understand how to maximise the extraordinary flavours of chilli, to such a degree that he has even developed a mulato and poppy seed salad dressing.

But perhaps Tessa Bramley, chef and joint owner of the Old Vicarage in Ridgeway, Derbyshire, truly reflects how chillies are being used in Britain. "We have to be careful how much we use," she says, "because no one buying a fine wine is going to want to have it ruined by too much chilli. But in the past few years, we have found that our customers have developed increasingly adventurous palates."

She uses fresh jalepeños, Scotch bonnets, Thai and yellow wax chillies sensitively in her dishes. A hint of chilli in a crab ravioli will bring out the sweetness of the crab, just as a tiny amount of red jalapeño prickles the taste-buds in a summery lime and pear dressing for John Dory.

There is no doubt for Bramley that the growing range of chillies is allowing chefs to discover new and subtle dimensions of flavour in their food.