Nothing sets the alarm-bells clanging in the critic's mind like the realisation that the star has a producer credit. Oh great, he or she will groan. A vanity project. A piece of indulgence that the star's pure clout has managed to get off the ground. Some long-nursed project they've dreamed of imposing on the world since high school. Perhaps it's something from the star's own fantastically delusional "production company", which in the corporate interests of kowtowing to the talent, has been given office space on the studio lot. Or maybe the film itself is something which the studio has, with clenched teeth, agreed to release as a condition for securing the star's continued participation in the lucrative action franchise that has made his or her name.

I can never think of the star's producer credit without remembering the passage in Hollywood producer Art Linson's memoir, What Just Happened?, where he has to tell an air-head pretty-boy star that his ugly new pseudo-intellectual beard has to be shaved off before filming can commence. The star/producer credit is a little like that beard, and has plenty of journalists grumpily reaching, as it were, for their razors. And I have to confess I was reaching for mine when I settled down to this movie, starring and co-produced by Julie Delpy. It is the story of a French woman and her American boyfriend, played by the saturnine Adam Goldberg, experiencing a fraught and life-changing couple of days together in Paris. There is, of course, an all-too-obvious parallel with Delpy's performance in the great Richard Linklater romances Before Sunrise (1995) and Before Sunset (2004), in which she played opposite Ethan Hawke, supplying some of the semi-improvised dialogue.

And it really did look at first as if Julie Delpy was just trying to clone that movie's reputation for a project of her own. But wait. As well as starring and producing, Delpy has written and directed the film; she has edited it and composed all the original music, and even contributed a family member: her father, the seasoned actor Albert Delpy, puts in a hilarious turn more or less playing himself. Two Days in Paris turns out to be a very likable, smart, offbeat film that, though not as emotionally telling as those Linklater films, and burdened initially with some silly affectations, is arguably funnier, and is certainly a technically accomplished, well carpentered piece of film-making.

We join the story as Delpy and Goldberg, playing Marion and Jack, return from a naggingly unsatisfactory romantic break in Venice and are about to spend a couple of days in Marion's family home in Paris before heading home to New York, where they have exemplary media-artistic careers; she is a photographer and he is an interior designer. For Jack, the nightmare is to meet Marion's parents for the first time, as he undergoes the embarrassment-Calvary of staying with her in her childhood bedroom.

Marie Pillet and Albert Delpy, playing Marion's impossible parents Anna and Jeannot, are terrifically funny. Jack witnesses a bizarre row between Marion and her mother, who has been looking after Marion's cat; she has discovered that her mother has been feeding it foie gras, thus rendering it morbidly obese. And Jack is very far from being a success with Jeannot, the ageing swinger-radical and bohemian, who scarcely troubles to conceal his contempt for the uncultured Yank.

The nightmare of dealing with his girlfriend's mum and dad is merely a curtain-raiser to a new problem. Jack is chagrined to discover that Marion has cheerfully shown her family an intimate photograph that she took of him on holiday, in a certain posture, and to his horror he finds a photograph of an old boyfriend of Marion's in precisely the same pose. This disclosure, coupled with her suspiciously warm encounter with old boyfriends on the street, ignites his paranoia that Marion is simply a serial monogamist, and that he is merely an exotic American conquest to be imminently discarded.

As well as Richard Linklater, Two Days in Paris is indebted to middle-period Woody Allen, and in fact Delpy sports a clunky pair of specs at the beginning of the film, which suggests she might be hinting at the comparison herself. There are family lunches and encounters at parties, in which Jack is called upon to explain and explain away his Jewishness, and there are encounters on the street with former sexual partners: encounters managed with no little drollery and sophistication. It is derivative, of course, and yet relaxed and stylish and charming. The only aspect of the film that tries the patience are the studied narrative voiceovers that Delpy goes in for at the top of the movie, illustrated with supercilious still-photo images in the Amélie style. But these quickly fade out.

What an eye-opener the film is. The time has come to stop patronisingly thinking of Julie Delpy as a blonde actress, and start giving her some respect as an auteur. She is now reportedly working as writer-director-star on The Countess, a movie about the notorious Blood Countess Elizabeth Bathory.
Vincent Gallo is a co-star. The time was when my heart would sink into my boots at this news: but now I'm looking forward to it.

Julie Delpy talks about some of the politics involved in Two Days In Paris, why the French don't like being criticised and why she would like to continue mixing writing, directing and acting in the future…

There are a couple of very barbed political conversations in Two Days In Paris, particularly about America and France. Is it true that the French have taken more exception?
Julie Delpy: They did. And I think the distributors got nervous because they don't want to offend anyone. Well, they don't mind offending Americans but they certainly don't want to offend anyone in France.

Is that because America has become quite an easy target?
Julie Delpy: They don't seem to mind some fun being made of their problems. I don't think they take it very personally. They have a sense of humour. Put it this way, I don't think Borat would have happened in France. It just wouldn't have worked because the French wouldn't have let him and it would only have come out in one cinema.

Do you ever find yourself having to defend any of the comments your character makes about the French?
Julie Delpy: Not so much to journalists, they've been OK. But some will get offended and I knew that when writing it. The French don't like to be criticised. I mean, Paths of Glory was forbidden for 30 years in France because it criticised the French army. They have good sides in that they're quite liberal and can talk about sex and all that, which Americans don't have so much. Something like [former President] Clinton's Lewinski story would probably never have happened in France because no one cares about a president's lovers and stuff. But on the other hand, the French don't like criticism.

You received an Academy Award nomination for your screenplay on Before Sunset. Has that helped to open doors for you and made it easier to get your own projects made?
Julie Delpy: A little bit but not that much - maybe because it was assumed that we were co-writing so it wasn't clear who wrote what. It's almost like people thought: "Oh, she's the only woman in a group of three writers so maybe she was just there, sitting on the couch being pretty or something..." [laughs] But I wrote the first draft and was very involved with the writing of that film.

Your next film is The Countess, about a 17th century Hungarian countess who embarks on a murderous undertaking in the belief that bathing in the blood of virgins will preserve her beauty. Have you started work on it yet?
Julie Delpy: Yes. We're currently preparing to do it. I'm going over costume design, set design and meeting designers and stuff. So it's very exciting. But it's a very big step for me and it's a very different film to Two Days In Paris. It's a drama but it's certainly interesting for me to be able to go from a comedy to a drama. I'd like to try as many different jobs and styles as possible.