What a generous hostess, and interviewee, Robyn Malcolm is. Would we like a cup of tea, a "burnt rock?" Yes, please. Would I like to see the placenta in her freezer? No, thanks.

The first thing she said was "I feel like I know you." That was sweet of her. Of course I feel like I know her.

People do. It's really Outrageous Fortune's matriarch, Cheryl West, they think they know. She once gave a speech to a women's group and afterwards someone said, "you're really nice, but we like the other one better".

What on earth did she say? "I said, 'I'm sorry to disappoint you'." And, putting on a plaintive little voice, "I can be a fun person too."

She really does have a placenta in the freezer. I already knew this because, what funny things we know about her. I wish I didn't know because, how disgusting. Is it next to the peas? "The pork chops. I'll show you.

Charlie's [her oldest boy] is under an apple tree and Pete's is in the freezer. I like ritual and I'm a romantic."

There is nothing romantic about a placenta in a freezer.

"Ha, ha. I think there is. Not romantic in a pink flowers and clouds way, it's just: why keep that stuff under the floorboards? I've got a couple of miscarried babies in the garden and I like having that stuff around me. Did you watch The Human Body? [There was] this amazing section on what that red jellyfish thing actually does. You're going green. I can show you if you want."

Does she sound like a kook? She is a bit nutty, as she would be the first to tell you.

"Oh, actors are nuts. I love them. I love nutty people."

She will tell you almost anything, although she denies being the "compulsive discloser", somebody once accused her of being.

"Oh, I don't think I'm a compulsive discloser but just, you know, why not communicate?"

She has had therapy since (this is a joke, but probably only just) she was "pre-verbal". Her mother is a therapist and her sister a clinical psychologist.

And, "150 years ago, you'd walk down to the end of the road and sit in front of the fire with your granny or your aunty and talk. Going and having a bit of shrinkage is a bit like that".

Also, she likes it because she gets to talk about herself. "Yeah, I was going to tell that joke. It's just another excuse to bang on about myself!"

"Actors will bang on about themselves for hours if you let them," she'd said earlier.

"Well, you live in a state of self-analysis ..."

It's a strange state to choose to live your life in, surely?

"Yeah, yeah. Deep narcissism, crossed with pathological subjectivity crossed with a kind of need to be liked. Richard Eyre, who used to be the artistic director of the National Theatre in London, once said that actors become actors because we are searching for requited love on a grand scale. And I don't know how many actors would baulk at that but I do think it's kind of true ..."

How narcissistic is she?

"When I was at drama school and I got dumped properly for the first time, my flatmate ... got me a bottle of whisky.

"So I was sobbing and you know, running the full tragic gambit ... and I went, 'this is amazing I have to look in the mirror!'"

And did she?

"Hell yeah. I was like, 'this is what real misery looks like. I must remember that'."

For a self-confessed, professional narcissist - hooray! I thought, an actor who admits to it - she seems without vanity. I don't mean to be rude, but if she did do her hair, she did it by running her fingers through it.

She's been voted Sexiest Woman on the Telly two years in a row; she's wearing Ugg boots.

She says she gets screeds of invitations to those A-list events but she likes to go home to her two boys and watch the telly. She sometimes goes to work in her pyjamas because she's going to be Cheryl all day, so there's no point putting on her own clothes.

Cheryl's life is obviously much more thrilling than hers, which she says is boring, so she gets very excited about what's going to happen to Cheryl next. (The season finale of Outrageous Fortune is on Tuesday night, TV3.)

I asked about Cheryl's appeal and she said a male journalist once said it was: "That she was a bit easy." A bit easy! "Which I thought was slightly reductive! She's Everywoman essentially." She's a slapper.

"Yeah she's a slapper. She smokes and she drinks and she swears. She drives her car too fast and she likes her sex and she's an okay kind of cook, but not brilliant and she's hot headed and bullish and bossy. I like all those things. I like the fact that she's imperfect."

Cheryl's alter ego is a nice person to pop around to see not least because her cakes aren't perfect (they're called burnt rocks for a reason), but surely she can't be fun.

I made a list of her causes: The Greens, Greenpeace, sustainable living, for breast feeding in public, anti-domestic violence and so on, sighing as I did it.

She said, "I know everyone is taking a bit of a swipe at celebrities attaching themselves to causes. But Greenpeace was on the front page of the Herald. You can be cynical about it ... but it works."

I thought she might be a boringly earnest do-gooder. For an earnest do-gooder she took that very well. She laughed, and said, terribly earnestly, "I am. I am. I'm a very earnest, furrowed brow, do-gooder."

She went to Fashion Week, which I'd have thought was a bit fluffy for her.

"I like frocks," she said. But, then, because she can be a bit earnest, etc, she said, "But I do have a real issue, honestly, that you're there in the front row and you watch these beautiful girls ... And I'm looking at them and I'm trying to relate to these clothes and ... we have nothing in common. I happen to menstruate and eat pizza. They look like under-fed, tortured sex slaves".

Why on earth does she go and look at them then?

"I don't know! I do like frocks. I went to see Pammy! She's got the most amazingly fake tits you've ever seen."

Oh all right, so she can be a do-gooder and be fun. We had a not at all boring time, talking about Pammy's bum, which was a relief after the placenta chat I can tell you.

Malcolm has a rather good bum - John Campbell once called it "magnificent" - and she showed it off on the cover of Metro magazine recently.

"Why not?" Or, why? "Oh, I thought it would be fun. I thought, 'if they want to put a naked 44-year-old on the cover of their magazine, good on them!' If I was one of the younger actresses on Outrageous Fortune I would probably be a bit more careful, simply because of the way it can be sexualised, the way it can be perceived."

I don't quite see why her image couldn't be perceived in the same way. "I'd quite like it if it was!"

She thinks she'll get a bloke when she's 83, "and have the best sex of my life".

And no doubt she'll tell everyone all about it.

She did volunteer that "compulsive discloser" information, which might rather indicate that she is just that.

I did ask her one question she wouldn't answer, about a bloke she may or may not have bonked. I didn't care either way: I just wanted to know if she did have limits. The answer is, yes, but not many.

We know about her piles, because she told a woman's mag. "Well, that was a baby story ... and sometimes you're in a doctor's surgery and you've got five minutes and you're in a doctor's surgery because you've got piles. I figure: 'Why not just be honest?"'

Hardly anyone else is.

"Well, that's the thing. I don't want to read: 'I pushed out three babies and it all happened at the drop of a feather and now life is perfect'. So, have I been defensive talking about piles? Probably. And I just have no shame!"

Which is what makes her so refreshing. She's talked about having an abortion. "I'm pro-choice."

She is private "about certain things". She says she won't talk about going a bit mad, in 2006. But she did, a bit: "I was pretty nuts."

She has said she is "quietly neurotic" about going out. Of course there is always the possibility that she was being "a bit dramatic when I said that!" Still, sometimes there is an unnerving blurring of real life and fiction.

"I am that girl who ... gets someone coming up to me, shaking and smoking a cigarette, saying: 'My baby died of cot death last week'."

The person they are confiding in is partly her, but partly Cheryl. "That's really confronting and it is quite scary. And I never know what to say."

She once walked into a cafe and a stranger said: "So, what kind of undies did you buy? They had friends who had been in a department store and seen me checking out undies and they'd obviously rung their friends." That is a bit creepy.

"Well, it's harmless but a little freaky. What amazes me is: Why would you?"

What rather amazes me is that she tells me (because, obviously, she's not just telling me but potential weirdos in cafes) that she now buys her undies online, from Agent Provocateur.

I went to the website and there was a picture of a woman in leopard-skin patterned knickers, a bit bondage-y and very Cheryl. Goodness. Why does she buy that stuff?

"I do it for me." And then she goes and looks at herself in the mirror?

"Yeah, I put it on and drink whisky, cry and look at myself in the mirror!"

See what fun she is?

She makes an interview feel like popping round to see a girlfriend. If your girlfriend happened to keep a placenta in her freezer, had had her naked bum on billboards, and happened to be the nicest narcissist you're ever likely to meet.