Joanne Harris brings us a wickedly mischievous tale of Christianity versus chocolate in Chocolat. Vianne Rocher, the mysterious newcomer to town, opens a chocolate boutique directly opposite the town church. With Lent fast approaching and the community's appetite for the good-life on the rise, Father Reynaud can't help but fear for his flock. It's up to the priest to save their souls before they consume too many eclairs of the damned.

When the exotic stranger Vianne Rocher arrives in the old French village of Lansquenet and opens a chocolate boutique called "La Celeste Praline" directly across the square from the church, Father Reynaud identifies her as a serious danger to his flock. It is the beginning of Lent: the traditional season of self-denial. The priest says she'll be out of business by Easter.

To make matters worse, Vianne does not go to church and has a penchant for superstition. Like her mother, she can read Tarot cards. But she begins to win over customers with her smiles, her intuition for everyone's favourites, and her delightful confections. Her shop provides a place, too, for secrets to be whispered, grievances aired. She begins to shake up the rigid morality of the community. Vianne's plans for an Easter Chocolate Festival divide the whole community. Can the solemnity of the Church compare with the pagan passion of a chocolate éclair?

For the first time, here is a novel in which chocolate enjoys its true importance, emerging as an agent of transformation. Rich, clever, and mischievous, reminiscent of a folk tale or fable, this is a triumphant read with a memorable character at its heart.

Says Harris: "You might see [Vianne] as an archetype or a mythical figure. I prefer to see her as the lone gunslinger who blows into the town, has a showdown with the man in the black hat, then moves on relentless. But on another level she is a perfectly real person with real insecurities and a very human desire for love and acceptance. Her qualities too - kindness, love, tolerance - are very human." Vianne and her young daughter Anouk, come into town on Shrove Tuesday. "Carnivals make us uneasy," says Harris, "because of what they represent: the residual memory of blood sacrifice (it is after all from the word "carne" that the term arises), of pagan celebration. And they represent a loss of inhibition; carnival time is a time at which almost anything is possible."

The book became an international best-seller, and was optioned to film quickly. The Oscar-nominated movie, with its star-studded cast including Juliette Binoche (The English Patient) and Judi Dench (Shakespeare in Love), was directed by Lasse Hallstrom, whose previous film The Cider House Rules (based on a John Irving novel) also looks at issues of community and moral standards, though in a less lighthearted vein.

The idea for the book came from a comment her husband made one day while he was immersed in a football game on TV. "It was a throwaway comment, designed to annoy and it did. It was along the lines of...Chocolate is to women what football is to men…" The idea stuck, and Harris began thinking that "people have these conflicting feelings about chocolate, and that a lot of people who have very little else in common relate to chocolate in more or less the same kind of way. It became a kind of challenge to see exactly how much of a story I could get which was uniquely centred around chocolate."

Rich with metaphor and gorgeous writing...sit back and gorge yourself on Chocolat.

"I'm a chocoholic! I admit it! I eat it all the time. Almost on a daily basis…but not quite." Joanne Harris starts the day with drinking chocolate made from milk and proper chocolate. "It's a stimulant. A bit like coffee. But it tastes better to me." She doesn't diet because "I'm not a nice person if I'm doing things like that."

Harris, who is half French, grew up in her grandparents' corner sweetshop in Yorkshire, in the north of England. Her mother had just come over from France and didn't speak English. Joanne grew up speaking French, and still speaks it with her own daughter at home. "Most of the family that I have contact with is French… I've been more or less surrounded by French culture since I was born." She associates chocolate with France, big family reunions and Easter parades. "A lot of members of my family ended up creeping into this story."

She lives with her husband, small daughter and several cats in the small Yorkshire mining community of Barnsley where she grew up. Harris feels that small communities the world over have much in common, and Barnsley sometimes felt like Lansquenet in its suspicion of the outsider - "because we were a French family, because my mother moved to England without knowing any English and because we were always those funny people at end o' t'road…"

How did she feel about her book being transformed into a big Hollywood movie? Various changes had to be made, including the fact that the priest figure becomes the mayor in the film. "I understand that when a book gets optioned you basically abnegate all responsibility for it." When the book was optioned, most of her attention was taken up with her next book, which she'd already started writing. In the end, she was extremely happy with the film. "I thought that the changes were quite minor and were really in the spirit of making it a better film." She even contributed a few changes of her own, mainly to do with the character of Vianne.

Is there any of Joanne Harris in Vianne Rocher? "Not as much as I would like… I think she is what I would have loved to have been but I am not in any way as confident as she is or indeed as popular. I think there is quite a lot of the priest in me as well." Like Vianne, though, Harris has a fascination with folklore and alternative beliefs. "I do tend to perform little good-luck rituals… I still cast the runes when I feel like it, and I enjoy making my own incense and growing and using herbs. I like to observe the traditional celebrations at Yule and at other significant times of the year."

Some readers have seen in Chocolat a comment on the Catholic church. Harris doesn't feel that way herself. "I never felt that this was to do with religious and secular - it is a story about personalities… It is about tolerance and intolerance."

The book is also about liberation and indulgence in the pleasures of life, and has struck a chord when many people, sick of the struggle to stay slim, and are feeling that a little indulgence can be good for the soul. Another British author Helen Fielding, whose Bridget Jones' Diary has also been adapted for the screen, created a popular character who grappled with diet over desire, and Canadian food writer John Allemang, in The Importance of Lunch, has written winningly on the simple pleasures of food. If Chocolat reminds us of anything, though, it's gorgeous, sensuous and romantic films such as Babette's Feast and Big Night with their celebration of food and life; similarly the Japanese film Tampopo, with its focus on a noodle shop, and the recent acclaimed Chinese film Shower, where a small community revolves around an old-fashioned bath-house. Small wonder Chocolat has been a massive international success.

Harris published two earlier books, both darker in tone - "I was aiming for a kind of literary horror/gothic genre" - and not nearly as widely read. Recently, her work is much more optimistic and fun, though she still tends to write darker stories when the weather is bad, and happy stories when the sun shines ("I wrote Chocolat from March to July, and it shows"). Since Chocolat, she has published two more books with mouth-watering themes: Blackberry Wine, narrated by a bottle of vintage wine, and The Five Quarters of an Orange, which contains recipes for crepes. "I come from a family where there is a long tradition of cooking and recipes are handed down from various parts of the family - usually down the French side." As the film of Chocolat was being released, she was at work on a screenplay for Coastliners, to be published as a novel in 2003, about two communities of villagers on a French island, fighting for a beach.

Harris reads widely in English and French, citing Nabokov and Mervyn Peake as major inspirational influences for their love of language. She taught French at Leeds Grammar School for many years and had been writing in her spare time when she hit the big time with Chocolat in 1999. Although she sometimes misses her former existence as a teacher, she is very happy to be able to make a living out of writing. "Giving up teaching was a very difficult decision for me to take; it was a job I enjoyed, and that I was good at, and I was very much aware that I was giving it up for something much riskier and, in some ways, something quite alien to my nature. However, some rainbows you have to chase." If writing for a living stopped giving her pleasure, she would go back to teaching "without a qualm". But she'd keep on writing.

"I know I''d write whether I was being published or not. I''m addicted."

Vianne Rocher moves to a small town in France with her daughter, and opens up a chocolaterie right across the street from the church during Lent. This offends the priest, so he tries to turn the townspeople away from her, thinking she's a witch. But his protests do the opposite. She receives a lot of business, and many people are willing to help her out. The town's outsiders are drawn to the chocolaterie, and many friendships are made. This book makes you fall in love with these characters and the atmosphere of small-town France. The author has a magical style of writing, with striking imagery that makes you feel like you are actually there.