As Sable, The Colbys' hard woman, and now as the despised mother in Beverly Hills 90210, Stephanie Beacham has become Hollywood's top superbitch. But the British actress says it all paid off when she built her Malibu retreat.

Her neighbours down the street include Sylvester Stallone, Dustin Hoffman and Goldie Hawn. The view from her bedroom window is the Pacific. And her back door is surrounded by a cluster of palm trees. But Malibu, says Stephanie Beacham, isn't all it's cracked up to be.

'It's boring, very, very boring,' she insists. Fortunately this is just the way the Buddhist actress who struck it rich in American soaps likes it. 'It's the perfect place to come back to after whizzing around in London or New York with the feeling that you've earned your walks on the beach,' she says. 'It's so quiet, you can't help feeling serene and unhurried.'

She bought her house five years ago with the proceeds from her tours of duty as rich bitch Sable in The Colbys and Dynasty, hurling insults at Joan Collins. It's an airy two-storey beach house in the modern Californian ranch style. This means white walls, Spanish roof tiles and the neighbours' Mercedes parked bumper-to-bumper down the road.

Inside Stephanie has opted for corduroy cream sofas, more acres of white walls and cool terracotta floor tiles. Her biggest extravagance is flowers (even her idea of heavy-drinking stretches only to six bottles of mineral water).

The living room opens on to the obligatory sundeck, but her favourite room is the upstairs withdrawing room - 'the peace and quiet room,' she calls it.

Not that the house The Colbys built would appeal to shoulder-padded, jewel-laden Sable at all. 'Not grand enough by half,' says the actress, currently back in the limelight as teen idol Luke Perry's mother in Beverly Hills 90210. But then she and superbitch Sable never did have much in common. Talk to most showbusiness people in Hollywood and you discover that Stephanie Beacham got to be Tinseltown's bitch of choice by being exactly the opposite.

'She was never late, never unprepared, she always knew her marks,' says her Colbys co-star Charlton Heston. As for Luke Perry, he's so enamoured of Stephanie the Beverly Hills 90210 director has to keep reminding him not to gaze so fondly at her on camera.

In addition to such testimonials, there is her charity work for the deaf (Stephanie is deaf in one ear). You begin to wonder if in person she won't turn out to be too good to be true. Fortunately there's a welcome asperity about her. At 46, she still wears leather jackets and isn't embarrassed to talk about parts that make actresses look less than glamorous - like Vanessa Redgrave in Howard's End. 'Yes, but Vanessa Redgrave's always been terribly keen on having a red nose and sniffing a lot, hasn't she?' says Stephanie with deadpan seriousness. 'She even had a red nose in Camelot. I remember it well.'

She talks of her own soap appearances in the plummy, never-say-die tones of a latter-day Joyce Grenfell who's been given the task of coaching the ailing sixth-form netball team.

'I know I can probably make a rubbishy old script work better than most so in I go, get my lines two days before filming, dash into wardrobe to sort out my costume changes, remark on what pretty petticoats I've got to wear and what nice people I'm working with, thank everybody for treating me so well, and then just wing it.'

Despite this no-nonsense manner, at the start of her career Stephanie was unofficially black-listed as a troublemaker and a promising film career disappeared before her eyes. 'I've not really talked about this before, but Sam Peckinpah told me there was a black mark against me in Hollywood because I was so unco-operative with publicity. I was an arrogant little thing when I left RADA and I just didn't see the point of publicity back then and I wouldn't do anything I didn't want to do, so the word went around and that was that.'

One reason for her unpopularity was her high-minded refusal to pose for Playboy in 1971 to help promote The Nightcomers, in which she romped naked with Marlon Brando. Stephanie didn't help matters much by promptly turning round a year later and posing for Playboy just because she 'fancied it'. The Academy of Motion Picture Science and Arts Library in Beverly Hills has the pictures in its archives. They depict a radiant Stephanie ('child of the counter-culture') entirely denuded, save for a negligible fur coat, a daffodil and a brace of puppies.

'I suppose I wanted to show I was my own person' she says today. 'Also, when they phoned me, I was in a swimming pool in Jamaica and had about three bits of string on me at the time. They said, "Will you do Playboy?" I said, "I'm practically doing it now."

'The thing is, I was just so unrealistic about the business then. I'd left RADA saying I'd make sensitive French films - not American ones because they're crude - I wouldn't do television, of course, and I'd work for the better theatres. Not a West End run, but the National Theatre, the Royal Court, that sort of thing. I didn't have a clue.' She soon got one. After stints with the RSC and the National Theatre and on British television in Tenko and Connie, she accepted the part of Beverly Hills harridan Sable in The Colbys.

The part had already been turned down by Faye Dunaway, Angie Dickinson and Diana Rigg, so it looked to be the career move of someone who had lost all their pretensions. But it did pay $20,000 a week.

'I took The Colbys because I was too broke not to,' was her explanation at the time. You wonder, though, if, after half a dozen years of interchangeable roles in multiple miniseries, she isn't beginning to feel somewhat stuck in a rut?

'Do you know, I don't know what I'm going to be doing next,' she says cautiously, 'but I do think that more of the same will get just a little bit tired very soon.'

As for Beverly Hills 90210, she jovially tells the story of being offered the part of Luke Perry's mum, apparently at the suggestion of Jason Priestley, who'd worked with her on the failed sitcom Sister Kate. 'Jas was my man,' she says, dropping into dead-on impersonation. 'He called Aaron Spelling and said, "Aaron, my man, it's Beacham for Luke's mum, isn't it?"

'So here we are, and we get on so-ooo well,' she adds, suddenly all mushy. 'Luke's lovely. Lovely, lovely, lovely,' she croons. 'And he's very cuddly, so we cuddle a lot. And he's surviving so well for being so much in the spotlight. From picking potatoes, or whatever he was doing a year ago, to just being the hottest thing that ever frowned - I mean, please...'

The little reverie out of the way, though, and Stephanie puts her tongue very firmly back in her cheek when I ask her about the character she plays. 'Well, I'm this dreadful hippie person who's always talking about auras and crystals and things,' she says. 'And I'm very hurt because Luke won't call me Mum. He calls me Iris. That's very hurtful to be called Iris. Can you imagine?'

Stephanie Beacham's obviously rather more proud of the bits of theatre, like a Los Angeles revival of The Vortex, she's fitted in among her television appearances over the last few years. 'The Vortex,' she says, 'was a jolly nice thing to have done.' And although she once told an interviewer she was perfectly happy to get her 'quota of grown-up, creative stimulation' from her real life, which includes daughters Phoebe, 17, and Chloe, 15, she also expresses a shy hope for a good film part or two.

One day she says she'd like to be disciplined enough to write a script of her own: 'I think all of us have got some sensitive, little well-observed film inside us, haven't we? It's just how the hell do you get anyone to pay for it? But wouldn't it be nice to have something where you could say: "I stand behind this with full integrity and without a sneer."