Whether or not Edinburgh crowds will recognise Margaret Cho probably depends on their TV viewing habits. British followers of Sex and the City may remember Cho as the terrifying, black-uniformed fashion producer who orders Carrie to model on the catwalk. She was the shouty, stony-faced one swearing loudly as Carrie tripped on her high heels and landed, knickers-up, on the runway.

Or maybe they’ll have spied Cho more recently on Sky Living’s Drop Dead Diva, playing another no-nonsense type in the fluffy, legal comedy-drama. Failing that, it may be only the US tourists in the audience who can place her face, which pops up regularly on American TV. Cho is something of a household name in the States, after she grew up on screens in the sitcom All American Girl, a show based around her actual upbringing above the San Francisco bookstore that her Korean parents ran. Soon she’ll be manning up in an episode of 30 Rock, as her fellow Korean Kim Jong-Il.

Whether or not Fringe audiences will warm to her comedy, however, is another story. A lot will depend on how they like their stand-up: boundary-pushing, gender-bending, potty-mouthed and accompanied by a banjo? Step this way. If they’re after something polite, heterosexual and shying away from bodily functions, they should perhaps turn to the next page in the Fringe programme.

Cho is nothing if not provocative. She’s the show-off at the party who will take that dare. She’s the one making talk-show hosts wince live on air. A crass, in-your-face attention-seeker, Cho waves an extended middle finger at decorum and any restrictive notion of what it means to be a modern-day queer. ‘My show is filthy,’ she states. ‘But it’s also fun, and I’m proud of it.’

Fifteen or so years after her All American Girl debutante days, Cho’s CV now has comedy, acting and singing on it, and she’s on her way to Edinburgh with a stand-up show based around her Grammy-nominated comedy album, Cho Dependent. So what delights can we expect? ‘Um, “Eat, Shit and Die”: I guess that’s a pretty good song,’ she offers, down the phone from America’s West Coast. ‘“Asian Adjacent” too – that’s about those people who look Asian, but you’re not really sure? You know, Meg and Jennifer Tilly? Björk? Where they could be Cherokee or Asian or Alaskan.’

Cho also intends to sing Edinburgh crowds through such anthems-in-the-making as ‘My Puss’, a rap about the virtues of her front bottom; ‘Calling in Stoned’, which harks back to her pot-smoking days; or ‘I’m Sorry’, a regretful murder ballad, originally recorded with quirky multi-instrumentalist Andrew Bird. Cho has no shortage of indie music pals as it turns out: Tegan and Sara show up on the album version of ‘Intervention’ and Ani DiFranco lends a hand with ‘Captain Cameltoe’.

In fact, the singing part first came about when Cho toured with Cyndi Lauper, who was highly complimentary about her voice. Cho’s impression of Lauper’s bubblegum New Yorker accent, urging her to ‘sing it loike it’s a lullaby to a lil’ chi-yuld!’ is a high point of her routine, as are Cho’s impressions of her dear old mum, the thickly accented, well-meaning Young Hie. Apparently Cho’s mum had a bad habit of leaving lengthy answer-phone machines probing her teen daughter on whether she was gay or not. Hearing Cho struggle over her mum’s verbs and consonants is a rare moment of cute in her stand-up routine, a glimmer of family affections and her softer, non-braggadocio side. But let us not digress; let us allow Cho to return to the smut.

‘I choose to be slutty,’ she declares, as a lap-dog-sounding animal yelps somewhere in the background. ‘When it comes to my sexuality, I’m beyond definition. Being queer is not about being sexy for me, it’s a political thing; it’s about being empowered.’ Cho’s personal life is very simple to her; although she acknowledges some people struggle to get their heads around it. Married to her husband Al Ridenour for almost a decade, Cho supplements this very ‘conventional, primary relationship’ with lots of other same-sex arrangements.

‘Being partnered is very important to me. But, being in a polyamorous relationship is just more honest for me. It’s more respectful to my nature,’ she explains, in the type of San Franciscan drawl than can’t help turning statements into questions. ‘I have poor impulse control!’ she laughs, before returning to a more serious tone. ‘Fidelity: I don’t personally agree with it? And monogamy doesn’t seem purposeful to me? But that doesn’t mean I would recommend my lifestyle to others either.’

And here emerges another trait of Cho’s, another very San Franciscan facet, almost as stereotypically caricatured as the drag queen friends and Haight Street hippies in her act. Cho loves to soapbox. Having taken stick throughout her life for being too Asian, too fat, not Asian enough, too thin, too queer, her outsider complex drove her at one point into a struggle with drugs and anorexia.

Now, stronger and more politicised, Cho has multiple axes to grind, and comedy is her sharpening block. ‘There is so much absurdity to conquer,’ she shrugs. ‘How is gayness societally problematic? I just don’t get that. And since when was someone’s ethnicity seen as something transgressive? There is such pressure to conform, and I really want to challenge that.’ So, besides entertaining crowds with the cabaret-style ditty ‘Eat, Shit and Die’ (the video for which features dancing stools of the non-wooden kind), Cho wants her comedy to be thought-provoking. Her puerile preaching is an outspoken call to arms that has attracted legions of fans, whether gay, straight, Asian, Caucasian: to her they are all equally fabulous.

‘It’s very moving to see so many different people in my audience,’ Cho has commented in the past about her shows. ‘I think for a lot of people what I do is more than entertainment; it’s a way of feeling like we belong, a way to feel validated.’ Does that mean the outsider has finally come in from the cold? ‘I’ll probably always feel like an outsider in showbusiness,’ she confesses. ‘But that doesn’t mean I don’t feel settled. I’ve spent so many years being miserable, now I’m just about being happy, and bringing the kind of discussion that lets others be happy too.’ Right on, Cho.

Words straight from Margaret Cho’s potty mouth

On being bisexual:
‘I don’t even care who it is anymore, I just want people to like me. I’m not “bi” I’m “I”. I just want people to be into me. I’m not a lesbian either, which is a shame, because I’m so good at softball.’

On Christian groups opposing gay marriage:
‘They have no right to call themselves Christians. They have no kindness to them, no compassion, no charity. I want Jesus to come back and be like: “THAT’S NOT WHAT I MEANT!”’

On her lack of Asian role models during childhood:
‘I would dream, maybe someday, someday, I can be an extra on M.A.S.H. Or a hooker in something: “Me love you long time?”

On CC Blooms:
‘They have one gay bar in Scotland, it’s called CC Blooms. CC Blooms is the name of the character Bette Midler played in Beaches. That is the gayest thing I’ve ever heard. That place should just be called “Fuck Me in the Ass: Bar & Grill”.’

On 9/11:
‘I got a chance to go down to Ground Zero. And I was there, day after day, giving blowjobs to rescue workers. We all have to do our part.’

On her upbringing:
‘I grew up in San Francisco on Polk Street. Some people were raised by wolves; I was raised by drag queens.’

On self-image:
‘I have a really hard time looking at myself. To me, I look like the Eskimo woman on Northern Exposure. I feel like I should be in The History of Man Museum, ice fishing.’

On Mel Gibson:
‘He’s not said anything about Asian people. I’m like, what about us?’

Margaret Cho: Cho Dependent, Assembly George Square, 0131 623 3030, 6–29 Aug (not 10, 17), 9pm, £15–16 (£13–14). Previews 3–5 Aug, £8.