Juliette Binoche totters in on improbably high heels, elegant in black trousers and a simple V-neck, her hair an unruly mop of curls — a startling new look for her next movie. She’s taken time off from the set in Paris to fly in to the Toronto International Film Festival for the world premiere of Breaking and Entering, in which she stars alongside Jude Law and Robin Wright Penn, and which will be shown in The Times BFI London Film Festival this month. For her this isn’t just any film: it’s a reunion with the writer-director Anthony Minghella, who directed her Oscar-winning performance in The English Patient ten years ago.

Binoche, now 42, plays Amira, a Bosnian refugee living in North London with her teenage son Miro (Rafi Gavron). When Law’s handsome landscape architect Will starts hovering around her she is flattered and surprised. It’s only later that she realises he came to track down Miro, who has twice burgled Will’s office. She can see that Will is in love with her, but she doesn’t know where it’s leading. Her solution to the predicament is both shocking and very human.

“For me it was exciting and a little bit frightening to play,” she says. “What Amira does is contradictory and painful. It’s not all white and black.”

I tell her how just a few minutes earlier Robin Wright Penn, who plays Will’s longsuffering partner Liv, had confessed that she was jealous of the French actress; she had really wanted to play Amira herself.

Binoche is serious but not too serious. And when she laughs, she really laughs: those brown eyes light up, she tilts her head back and peals. “'No! I think maybe she wanted Jude’s part!” She regains her composure.

The film marks a significant change of pace for Minghella. It’s his first original screenplay since Truly, Madly, Deeply and his first film set in Britain after a string of literary adaptations: The English Patient, The Talented Mr Ripley and Cold Mountain.

“This one is closer to his bones,” Binoche says. “I think he went through films that brought him back to himself . . . if your films don’t belong to you, then you’re losing yourself. But I felt the subject was still big: a Bosnian woman surviving in the big city, fighting for her son and letting love enter into her life. These are frightening issues, so I felt responsible for taking them on. And I wanted to take risks. I hadn’t done a love scene for a while, but I had to allow it, otherwise there is no commitment somehow. You can’t only commit with the head, you have to commit with your whole body as an actor.”

And yet she has refrained from sex scenes of late, a far cry from the uninhibited erotic abandon that marked her breakthrough performance as Tereza in The Unbearable Lightness of Being, nearly 20 years ago now, or several of the films that followed, such as Les Amants du Pont-Neuf (1991) and Damage (1992).

“I felt like there were a lot of sex scenes in the movies I had done in the late Eighties. Probably too many,” she says now. “There were requests almost on each movie, and I had to fight against that. Kieslowski wanted me to be naked and walk in a room in Three Colours: Blue and I said: ‘Do you know how many questions I have about sex scenes in the movies? What does it serve in the movie?’ And he thought about it and said: ‘No, we won’t do it’. Because he understood it wasn’t necessary and it’s a burden for an actress.”

The sex scene in Breaking and Entering is a pivotal dramatic moment that reveals more about Amira than her body. “There is a reason for it, and it was part of my trust in Anthony.” She shrugs. “We didn’t talk about those things. I felt protected.”

It’s dismaying to learn that Binoche almost gave up movies altogether after Les Amantsdu Pont-Neuf, her third (and last) film with the director Leos Carax, and a long, exhausting shoot that went on for more than two years. “It was too hard, too difficult, too painful,” she recalls. “I went back to my acting teacher and said: ‘I want to stay here at the studio and watch and listen — it’s wonderful just watching these young actors transform before your eyes’. He said: ‘Fine, we can do that, but you are going back to acting. There is no other way!’ So it was a pact I made with him to carry on.”

Three Colours: Blue in 1993 was a turning point — the ingénue coming of age and emerging as a totem for arthouse sophistication. Women responded especially strongly to this soulful portrait of grief, self-abnegation and recovery. Three years later the Canadian nurse Hana traversed similar emotional territory in The English Patient. It remains perhaps her best-known role outside France, and certainly another of her most moving performances.

She recalls that she was so frightened before shooting The English Patient that she was shaking. “I was trembling so much I had to take drugs, I thought it was going to show!”

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