Goodbye frumpy Fran

Most of McDormand's early film roles were deliberately unglamorous and often had a challenging social edge. She earned an Oscar nomination as the downtrodden wife of a racist bigot in Alan Parker's civil rights thriller Mississippi Burning (1988), then played a hard-bitten journalist investigating shoot-to-kill allegations in Ken Loach's drama set in Northern Ireland, Hidden Agenda (1990). In between she worked with underprivileged children at the 52nd Street Project charity theatre workshop. But her dream job, bizarrely, remains the poorly paid grind of stage work.

'There was a whole kind of path through classical theatre that I intended to move through, but having to pay rent and make a living as an actor quickly made me realise that I wasn't going to get to all of them,' she shrugs. 'That's why I have to play the movie star's girlfriend every now and then, so I can do theatre.'

When McDormand finally became a household name in 1996, it was largely thanks to the Coens again. The brothers wrote and directed her role as Minnesota policewoman Marge Gunderson in the deep-frozen black comedy Fargo, making Marge pregnant purely because they were amused by the notion of photographing 'a big round turd in a big white landscape'. The Coens warned investors that this bleak little kidnap yarn was unlikely to recoup a profit. But it actually made more than $25 million on a budget of $7 million, and won Oscars for Frances, Joel and Ethan.

As indie film-makers based in New York, they felt like 'marginal film-makers invited to this industry thing'. But Marge Gunderson had struck a populist nerve and McDormand was suddenly a celebrity, an unexpected role which she still does not relish. 'That's a whole job, isn't it?' she sighs. 'I really enjoy my life, and I prefer a private life. That's been the hardest part of it, that it's bled into my personal life. I mean, often I'm approached by people who want to do the Minnesota accent for me - it's like, "Oh no, I don't want to listen to your Minnesota accent".'

How does McDormand cope with fame? She ignores it and hopes it goes away. 'Generally I just try politeness because it seems to get it over with the fastest,' she shrugs. 'Sometimes it's so inappropriate, but I don't want people to be aware of how inappropriate it is because it happens once maybe in their life, and it happens every day to me. But it also coincided with becoming parents, and that's been one of the hardest things for me to incorporate.'

Frances and Joel married in 1993 and adopted a Paraguayan son, Pedro, a year later, after 'nature didn't come through'. In her Oscar acceptance speech for Fargo, she thanked 'Ethan Coen, who made an actor out of me, Mr Joel Coen, who helped make a woman out of me, and my son, who made a real mother out of me.'

But fame and parenthood, she argues, are not a great mix. 'I want our son to know that we have work that we love to do, and that someday he'll have something he loves to do, too,' she explains. 'So it's very hard to explain to him why people are always saying, "Love your work, love your work". He's six years old and he is, of course, for me, the centre of the universe and people are always going, "Photo, photo, love you, love you". He doesn't always understand why it's coming in my direction and not his. That's a very hard thing as a parent to help him with, so I'd rather just not be a part of it.'

Another way to shun the trappings of fame is to avoid taking obvious careerist roles, as McDormand has. Most actors would use an Oscar as leverage to grab high-profile work in Hollywood blockbusters. Instead, she rang around her favourite low-budget directors, offered her services dirt cheap, then went back to off-Broadway theatre. 'There's a continuity to it,' she says of her love for stage work. 'And it also is just so much more practical for my personal life.'

Immediately after Fargo, McDormand took a few cameos and indie roles. She chose Madeline (1998) because it meant spending summer in Paris with her family - Joel and Pedro travel with her almost everywhere. Then she returned to a play she had tackled before, A Streetcar Named Desire, at Dublin's Gate Theatre. But this time she switched parts and played deranged temptress Blanche, a femme fatale in corsets and stockings. It was this performance which partly inspired Doris Crane in The Man Who Wasn't There.

McDormand was tempted back to the cinema for key roles in two of last year's most acclaimed mainstream films, Wonder Boys and Almost Famous. In the latter, she played the teenage narrator's neurotic mother. 'I haven't wanted to play a mother for so long because I am one,' she declared.

Neither film was a huge commercial success, but both were critical hits - indeed, Almost Famous brought her yet another Oscar nomination, and another traumatic trip to the Academy Awards. Flying in from New York and finding a fancy frock, she sighs, was simply 'a pain in the ass. It's just impractical in my life,' she frowns. 'I don't have time to look for gowns. I don't live in LA so it means flying to Los Angeles, arranging for our son, you know - it's a drag. It sounds ungracious but I'm just being as objective as I can?'

This sounds like our old friend, frumpy Fran, modestly underplaying her own gifts once more. But she also makes a serious point about the absurdity of actors winning prizes instead of interesting roles. 'What's unfortunate about it is that, even in a category of five women in a supporting role, they keep inviting the same people back over and over again.

That means there is not enough work being generated, because there are fabulous actresses my age working in supporting roles in film. There needs to be more work for them.'

McDormand's latest film role is in the forthcoming Robert De Niro cop thriller, City By The Sea. Up next is a touring production with avant-garde New York theatre outfit, The Wooster Group. And then what?

'I'm interested in really specific things right now, both in theatre and film,' she says. 'My last job was one that I did to support my theatre work, and waiting for the kind of part I want to do. I'd like to do some nudity, and I'd like to do a musical.'

Nudity? Is this the same shy, retiring Frances McDormand who once slammed nude scenes as 'demeaning' and a personal no-go area because of 'huge insecurity' about her body?

'Definitely!' she grins. 'Forty-four is unkind, but I want to show it. Get some cellulite, some stretchmarks - I'm ready to put it out. With good lighting! Ha ha! But I'd like to show it.'