Margaret Cho is sitting in her bath gown in her home in Los Angeles with her dog at her feet and her phone in her hand, discussing definitions of queerness, the gay secrets of the Republican Party and her open marriage.

And it’s only 10 in the morning Pacific standard time. Decorum? Frankly, that’s just a place in Pennsylvania (it is; look it up).

To be fair I’m the one asking her about such things, but Cho has never been backward about coming forward. If you don’t know her, imagine Frankie Boyle if he was a Korean-American, heavily tattooed, gay-friendly, bisexual ... Actually I’m thinking this analogy is already a bit too stretched. Okay, think of it this way. When it comes to stand-up comedians, Cho is edgy in the way that the White Cliffs of Dover are edgy. How so? Well, this is her on Sarah Palin (and hey, public health warning: don’t read on if you’re easily offended). “I hate Sarah Palin, I hate her politics, but I kind of want to f*** her.”

Are we clear? This is a woman who has done routines about defecating in her car and who in interviews (not this one, but then I’ve never been to Pennsylvania) compares the size of former boyfriends Quentin Tarantino and Chris Isaak’s respective, ahem, manhoods (Chris wins, if you’re interested, but neither has anything to worry about). She does, however, suggest that the spouse of one senior Republican figure is “blazingly gay” but in the closet (blazingly gay not being “in” among the Tea Party crew this term). Would it surprise you to learn that she used to tour with Bill Hicks? Thought not.

“For me, performing is a political statement in and of itself,” she says, “I’m Asian-American, I’m a woman, I’m queer, I’m not what people would think of when they think of a stand-up comedian.”

Okay, okay, she’s definitely nothing like Boyle. Instead she is an outspoken 42-year-old woman raised on Joan Rivers and Saturday Night Live who is going to spend the rest of the day doing restorative yoga and who plans to do some drinking when she comes to Edinburgh for the Festival because last time around – some 10 years ago – she didn’t, “and I don’t want to do that to the Scottish people. I felt like I did Scotland wrong”.

Cho was brought up in the Polk district of San Francisco, which along with Castro, is a “gaybourhood” (it’s the one where Armistead Maupin’s Tales Of The City books are set). “My family had a book store that catered to the gay community. It had photography books, art books and fashion and fine literature. And gay porn, a lot of gay porn.”

Her parents were typically Korean-American in that they worked hard, but perhaps not so much in other ways. “My father wanted me to be schooled by gay men. He felt gay men were superior in terms of culture and art and they knew everything about fashion. He wanted to create this superwoman. He left me in the care of these very tattooed, very flamboyant gay men. That’s one of the reasons I’m tattooed. When I became an adult they took me to Ed Hardy who tattooed me all over my entire body, so I have this physical memento of my growing up.”

As someone who finds the idea of a needle filled with ink being jabbed repeatedly into my arm (or anywhere else for that matter) a tad unappealing, I have to ask her the obvious question. Did it hurt? “My threshold for vanity is greater than my threshold for pain.”

Hard to believe but she says she was a shy kid. She thinks she still is shy. Which doesn’t quite square, I suggest, with going on stage and talking about her orgasms. “You still retain the shyness,” she counters. “A lot of performers I know are painfully shy.”

Actually she thinks she was as much bewildered as shy when she was a child. If San Francisco seemed a beautiful, idyllic place in the 1970s, that began to change in the 1980s. “Aids happened. This tragic plague where people were dying every single day and you could see the evidence of that every day in the streets. You would see people get weaker and weaker; one day with a cane, one day in a wheelchair and one day gone. To witness the deterioration of people day by day is so painful, people that you know, people you love. It was so horrific. Many people that raised me and that I loved so much died. It was just unbearable.”

When she was 16 a gay teacher who did more than most to encourage her writing didn’t come to class one day. Later she overheard boys explaining why: “That faggot got murdered”. Her teacher was beaten to death in an act of homophobic violence, an act so terrible her childhood ended there and then. “I couldn’t bear being a child any more. I couldn’t bear being told all these tragic things any more. I wanted to be an adult so that I could somehow bear it. I missed out on a huge part of my life. It would have been a problem had I not been in showbusiness where childishness and childlike behaviour are rewarded.”

Not immediately, as it turned out. She left school and began to pursue a career as a stand-up only to be poached by TV to star in the first Asian-American family show ever. She could see her name in lights and at the time it’s what she wanted. “I thought I had such a tough time as a teenager that I deserved this acceptance. I put too much stock in the idea that fame would solve all of my personal problems or that fame would somehow make me feel good about myself.”

It didn’t work, though. She found herself hounded by TV execs claiming she wasn’t, umm, Asian enough. And she certainly wasn’t skinny enough. “The major complaint was that I was considered too fat to play the role of myself. I went into this crazy, anorexic phase. I was hospitalised and then the show was cancelled because I still wasn’t thin enough. It was this really traumatic thing. I ended up writing about it and making a film about it which was a very big success. I became a stand-up comedian again, which was really my true destiny. Actually it was a good thing.”

Really? It led to a drug and alcohol addiction, didn’t it? “I would go with substances if I couldn’t eat. If I took drugs it was speed. It was about ‘how do I not eat?’ All of that is pretty much solved if I’m eating because actually that’s my drug – food.” These days she’s realised the meaning of life. “I think it’s just figure out a way to enjoy it that won’t kill you.”

Cho got married to writer and artist Al Ridenour in 2003. She knew her husband for years as friends. “We were both partnered with other people and then we decided we were going to run away together with our stuff. It was an immediate, middle-of-the-night thing and it was horrible for the other people involved and it was probably a very selfish thing. But it was the right thing to do.”

In many ways, she says, it’s a conventional marriage. Well, other than the sex. She still defines herself as queer. “I don’t believe in monogamy. It’s dishonest to me. My marriage is open but it’s also very conventional. I have had sex with men and women. You don’t turn straight because you’ve decided to have a straight partner.”

Good to know. Actually, I say, it is telling that anyone whose sexual choices tend to the vanilla palette don’t find themselves defined by their sexual preferences in the same way as those who like to mix and match their flavours. “For me, my sexuality includes so many different aspects which I have to constantly define and talk about, which is okay. But it’s true if you’re straight you don’t take that to work.”

It’s time for the restorative yoga. If you don’t know Margaret Cho yet here’s a few other things I can tell you about her. She has a Region 2 DVD player which allows her to watch all her favourite British comedy – The League Of Gentlemen, French & Saunders, Human Remains and The Mighty Boosh. She’s just written her will. Quentin Tarantino calls her Maggie and she calls him “somebody I will always love”. She’s just spent the previous weekend in San Diego marching with the military in a Gay Pride march and when she’s in Edinburgh, as well as go to the pub, she is going to sing some songs, meet old friends like Neil Gaiman and Amanda Palmer.

Who is Margaret Cho? This is what she thinks: “I’m really unusual, but not unusual to myself.”

Margaret Cho: Cho Dependent is at the Assembly Rooms George Square from Saturday (not August 10, 17), 9pm (previews from Wednesday)