JEAN-PIERRE Jeunet is not a great fan of reality.

Not for him the current French wave of cinéma-vérité typified by the three-hour long relationship drama Blue is the Warmest Colour.

"It's absolutely not my cup of tea," he says of the realist film-making mood in his native France. "I feel like a painter, I love to modify colours, to change the world."

Having done so with Amelie, his 2001 global hit, Jeunet is up to his world-transforming tricks again with the equally delightful The Young and Prodigious TS Spivet, out next week.

Based on the novel, The Collected Works of TS Spivet by Reif Larsen, the picture tells the story of a genius from Montana who creates a perpetual motion machine. Having won a prize at the Smithsonian Institution in Washington, TS, played by Kyle Catlett, is invited to collect it. What he has not told his hosts is that he is just ten years old. That is not the only secret TS is carrying with him.

Jeunet raced through the book. "I was thrilled by the awesome character, by his moving story, by the wealth of detail and also by the ambience, the trains, Montana, the wide open spaces."

Meeting its young American author, the Delicatessen director was reminded of himself 30 years ago. "We must be part of the same family: we have the same tastes, the same obsessions, the same enthusiasms, the same attractions."

The comparisons do not end there. Given TS's boundless imagination and endless inventiveness, it is not hard to see a likeness with the young Jeunet.

"Kind of," he says when I ask if he was a TS-type of child. "But I was not a genius," he laughs. "I started to make films very early, probably at eight or nine. I built a play theatre with puppets, making the sets, the costumes, writing the story, and doing the lighting."

Later, he used a View-Master stereoscope to make a film with his friends. It was his first taste of 3D, a form which was to lend itself naturally to bringing Larsen's book, and its artwork, to the screen.

Although Jeunet had fallen in love with the notion of the wide open spaces in Montana, he only set foot in America once.

"While scouting locations I visited a location with a barbed wire fence across it. It was the border. I just stepped over to the other side." This being a French-Canadian production, the cast and crew set up on the Canadian side of the border instead. "It's the same mountains."

Shooting in Canada gave him a sense of freedom he would not have had in America, he says. Although he has worked in LA - he helmed 1997's Alien: Resurrection with Sigourney Weaver in Hollywood - Jeunet is not a director who likes to feel fenced in. He turned down the chance to film one of the Harry Potters, reckoning that there was not much scope to do his own thing.

"With this [type of] film, everything is ready, everything is on the table, the production design, the casting, the costume, you don't have anything to create and I thought it would be boring just to shoot the film. If it was today maybe I would say yes, but that time I said no. You have to listen to your heart and it wasn't the right timing."

One of the biggest problems on the TS Spivet shoot was that Catlett was also making a US television series at the same time.

"Luckily, he was shooting in New York and not Los Angeles. Kyle travelled at night, he left in a helicopter, we worked weekends. But none of that kept him from being extraordinary."

Jeunet's heroine this time is Helena Bonham Carter, who plays TS's mother. The two first met in 1999 and the English actor told him, in perfect French, that she would like to work with him one day. Jeunet never forgot, and Bonham-Carter was as good as her word.

He sees a lot of his previous muse, Audrey Tautou, in the Alice in Wonderland star. They can both do anything he says, be funny one minute, portray intense emotion the next. "It's such a pleasure to work with this kind of actress."

Mention of Tautou takes us back to Amelie, the tale of an oh-so-French good Samaritan. Nominated for five Oscars, it changed everything for Jeunet and his star, who went on to appear in the The Da Vinci Code and in Jeunet's next film, the Oscar-nominated, First World War drama A Very Long Engagement. He will always have a soft spot for Amelie. As will millions of others.

"It's still a pleasure to go to the Amelie cafe in Montmartre and see people taking pictures. Every four minutes, can you believe it?" He is just back from Brazil, where the cult of Amelie is still so strong he met people with tattoos of Tautou.

"It's the dream of every creator to write something very personal and see it become a success," says Jeunet.

The Young and Prodigious TS Spivet opens in cinemas tomorrow.