I have been warned not to meet Camellia Panjabi, creator of the Masala Zone restaurant chain, on an empty stomach. She talks about food in a way that makes your mouth water. I am glad I stopped off for lunch beforehand at Amaya, one of her six London restaurants, and the first to receive a Michelin star. After the special lunch plate - which included the best daal, spicy chicken and pomegranate raita I have ever eaten - I am ready to kiss her feet.

Credited with introducing regional Indian cooking to the UK, Panjabi is a legend throughout the culinary world. Born in Mumbai (she will not reveal her age), Panjabi studied economics at Cambridge and went on to become the marketing director of India's most prestigious hotel group, Taj Hotels, of which she remains a director. She is also one of the directors - along with her sister and brother-in-law - of Masala World, which owns Chutney Mary, Veeraswamy, Amaya and three Masala Zone restaurants in London.

I catch up with Panjabi, who divides her time between London and Mumbai, at the Masala World head office. She is quick to tell me why many Brits have Indian food all wrong. "There is no such dish as curry," says Panjabi. "It is a sauce, not a meal."

Over the last 20 years, she has travelled around India introducing little-known dishes - such as lamb with turnips and watermelon curry - to eateries in high-end hotels there. She also brought Szechwan and Thai cuisine to India. "The most popular cuisine in India for eating out and takeaways is Chinese," says Panjabi, "but most people order chicken manchurian, which does not exist in China; it's like chicken tikka masala here."

In 1982 she set up the Bombay Brasserie in London, serving straightforward Indian dishes, such as aloo tuk (potatoes with yogurt and tamarind), and paneer goli kebabs (cottage cheese and potato balls with pomegranate and fig chutney). In 1992 the restaurant served its millionth customer.

Panjabi has just sold the millionth copy of her seminal cook book, 50 Great Curries of India. "The story of the book is a fascinating one," says Panjabi. "I had tried to introduce proper regional Indian food to the hotels, but I was told, 'No one will order them.' I was convinced they would, and put real Indian dishes on the menu rather than meat swamped in curry sauce. But they didn't order them. I decided that I had to educate the public about real food before experimenting." So she began research for her book. "I tried all the top publishers in the country, and all of them said there was no market," she says. Did she ever lose faith? "Never," she insists. She guessed the book would appeal to both men and women but in different ways. "I knew curry-making was a macho thing men would want to do at the weekend," she says, whereas, "Women were hesitant to cook curry for dinner parties, as they did not want to get saddled with something they could not do."

Many chefs in both Europe and India have reason to be grateful to Panjabi. She mentors her cooks, and those who embrace her philosophy (no pre-prepared sauces, no frozen food, and all spices ground to order) are given unparalleled opportunities.

"I often lend my chefs to European restaurants, so they can learn about French and Italian dishes; they in turn teach those chefs about Indian food," says Panjabi. "Many of my chefs are now working in top-class restaurants all over the world, and lots of them are still in touch with me."

Young chefs coming from India to work for Panjabi in Europe are given accommodation in large apartments together, to counter the loneliness of being so far away from home. Panjabi admits, however, that she does not employ female chefs. "It is too much responsibility. It could be too complicated - how would she get home after midnight alone?"

Panjabi starts telling me how spices work, how to chop, and which vegetables work with particular flavours. Once again, I am grateful I ate earlier. As she speaks, you can almost hear cardamon seeds popping in hot oil, smell the ginger and garlic browning, and taste crispy onions and daal. She talks of how important it is to explore the relationships between colour, smell and taste, such as the beautiful purple hue of an aubergine, and the silky texture and burst-in-the-mouth flavour of the spices that can rescue it from blandness.

What does she cook at home? "I love rice and daal," says Panjabi. Sitting in front of the TV? "Oh never," she giggles, "Eating is far too serious to combine with anything other than the sight of the ocean outside my window in Bombay."

But how did she develop such an obsession with food? "My mother loves food, but it was my grandmother who really taught me to cook. The whole family would talk of food and ingredients - what we were eating that day - constantly."

Panjabi's favorite dish from childhood? "Bhuna gosht, home style. There is nothing like it." The dish, consisting of lamb, stir-fried in cardamom, cinnamon, ginger, chillies and a brace of other spices, is now on the menu at Chutney Mary. Panjabi's real passion though is a variation on Indian street food. "Street sellers depend on word of mouth. So they have to make it taste the best," she says. "My mother did everything in her power to stop us eating it, but with children there is always a way. That love of the taste of street food stays with us through to adulthood."

What is she looking forward to in the future? "Three more Masala Zones opening in London, with more thalis on the menu, and more vegetable dishes than ever." Panjabi predicts that vegetables and vegetarian dishes will become far more varied and easily available in the near future in all types of UK restaurants. With her reputation as a serious trendsetter, I feel inclined to believe her.