Jennifer Saunders seems very relaxed, her booted feet up on a pouffe, snuggled in a big woolly cardie, sipping a mug of tea and talking openly about everything from the menopause to depression, cancer and her empty nest syndrome. Oh, and there are a few laughs, too.
The last time we met, six years ago, she had mixed views on the future of Absolutely Fabulous, the show she created, two decades ago now. On the one hand, she felt that perhaps its time was over: "You have a sense of when something's really past its sell-by date and it might just be now."
And on the other, "Generally, I think there are more jokes than in the average sitcom, so why shouldn't I do another one?"
But there was no doubt at all how much Saunders loved her creation and playing her: "I absolutely adore her and I adore being her. When I'm being Eddy and Joanna [Lumley, of course] becomes Patsy, I think there's no happier place to be, because it is total escape. It must be, for us, like meditation is for other people."
So after an exceptionally tough year - dealing with breast cancer and its aftermath, which she brings up herself, slightly surprisingly - Saunders has experienced the bliss of being Edina again for three specials honouring Ab Fab's 20th anniversary (it began in November 1992 on BBC2).
We meet in her London office, above a shop in Notting Hill. She and her husband, Adrian Edmondson, still have their home on Dartmoor but they've recently bought a house in Bayswater, too, and Saunders is having a gas, lunching for England with all her old girlfriends.
Post-chemo, on the plus side, her hair has grown thicker than it's ever been and it looks ab fab, in the best sense - above her striking features (good bone structure) - all wayward layers and messily fashionable.
The new Ab Fab shows Eddy and Patsy, who are now in their 60s (Saunders is, in fact, 53; Lumley, 65), trying to keep abreast of the modern world of tweeting and blogging while still clinging resolutely to their outrageous outfits, fags and Bolly.
All the gang are there: Eddy's evermore- forgetful mum; Saffy (still sensible after all these years - "I was missing the relationship with her and wanted to know how that would pan out"); and nutty assistant Bubble, who does a particularly bonkers demonstration of Pippa Middleton's famous bottom coming to life at the royal wedding.
Edina has the good taste, we agree, to be in thrall to the Danish thriller The Killing, and so viewers are treated to a cameo by Sofie Grabol as Sarah Lund, who appears in a dream.
Other guest stars include Lindsay Duncan, who plays a major role in the second episode; Lulu, who's already tweeted about it and posted photos; Emma Bunton (aka Baby Spice), La Roux and Stella McCartney. Kelly Holmes ("She looks so toned; I sense that even her brain is toned") and Tanni Grey Thompson appear in the third show, which has an Olympics 2012 theme.
When I say that, to me, Eddy and Patsy don't really seem to have aged that much - although in 20 years they obviously must have done - Saunders thinks it must be something to do with it not being so noticeable because their behaviour hasn't really changed.
"What I love about them is that there's very little you can do that would seem unreal for them. I quite like that kind of cartoonyness about them.
"Patsy is, on the one hand, this sophisticated, drug-taking woman and on the other, she's semisenile and demented and doesn't even have a wallet or any money. I think they're entering a new phase in which they can't keep up with everything. Eddy sometimes doesn't know what the new clubs or fashion designers are because you can't fit that much in your head."
The more Saunders talks about her character, the more poignant Edina sounds.
"Everything she's ever tried not to be is happening to her. It does sound a bit tragic, but as she's now 60 - and grieving for the menopause - there's very little time for her to become the fabulous person she's always wanted to be. It's always been a case of, 'I will be thin. I will be clever. I've got lots of time.' "
Saunders has decided, having been anti the idea for years, that it would be worth doing an Absolutely Fabulous film, which she may well do after finishing her Spice Girls musical (of which more anon):
"It would be about Patsy and Eddy being in search of what they could never achieve - the glamour, the slowness of life and the style of the dolce vita.
"Because the world has caught up with them. Everyone wears stupid clothes. Everyone shows their knickers as they get out of a cab. Everyone is Edina now."
Saunders has mixed feelings herself about ageing: "There are things that annoy you about it and things that aren't so bad about it." She admits to being reasonably vain and loathing - who doesn't? - a bad photograph of herself:
" 'Oh, remove that one, love… Cut, cut, cut… Delete, delete, delete.' I care what I look like at the beginning of the day and try to make myself look better - but I don't really care during the day."
At one point, we have a good moan about the menopause. "Ade was shivering in the house the other day and actually pulled a sheepskin over himself. I said, 'Why don't you turn the heating on?' And he said, 'Because you're hot all the time. And then cold. And then hot. And then sweating, and then not sweating.' "
It was her breast cancer that ushered in the onset of the menopause, which is far more extreme, apparently, because the drug Tamoxifen blocks your oestrogen: "So you are pushed into menopause like jumping off a cliff… bang!"
She was diagnosed last year, after spending her summer holiday with a girlfriend who'd just had breast cancer herself. Saunders is usually religious about having an annual mammogram, but had missed her last one because she was on tour.
Now she's a mammogram evangelist: "I always tell my girls, 'Mammograms and smears - they seem like a big thing, but it's nothing. In and out - just do it.' "
When Saunders talks about her treatment at an oncology unit in London's Harley Street, she has something of the same gleam in her eye as Eddy extolling the shopping glories of Harvey Nicks:
"It's massively new and I became quite addicted to my old chair and my nurse, who was very good at stabbing me - you know, getting the portacath in - because, I can tell you, you don't want any fiddling about. He was an absolute joy. I sort of miss him, really, and those social visits."
She had six months of chemotherapy, with weekly visits in the last three. These were bad enough, obviously, but, "You just grit your teeth and bear it." Her way of dealing with the cancer was to take a pragmatic approach:
"It becomes your job and your job is now getting through this next year of whatever - and in a funny way that releases you to say, ' What do I have to do today? Oh, I have this or that hospital appointment' - although I did find it quite odd, the number of hospital appointments."
Saunders was unprepared for how she felt when the treatment was over. "I found the Tamoxifen [which she'll be on for five years] the hardest thing because it changes you.
"It's like suddenly becoming older. You feel fagged out, you lose your motor and it makes you feel depressed. You have that 'I want to go to bed and sleep for ever' kind of feeling. Normally I have the energy to get up, get ready and do something, but I wasn't starting my days until maybe 11 or 11.30, even though I was awake."
It was one of her best friends, psychologist Tanya Byron, who made Saunders confront the reality that she was suffering from depression. "I'd say, 'The whole world is against me. Everyone else is wrong about everything.' And she'd say, 'No, darling, I think that might be depression.' "
In the end, Saunders did take the antidepressant Citalopram: "And, honestly, it was, like, 'Give me more pills!' It was brilliant."
How did her husband and their three daughters (in their 20s) cope?
"Ade was all right, actually He's a sort of rock in that he never gives anything away and he's very good at letting you get on with it. I think he was very strong about that. And the girls were brilliant. Freya was at home most of the time and was fantastic. And I have really good girlfriends who'd come and look after me and sit with me in the chemo sessions.
"I have to say I thought quite a lot of it was hilarious - because once you get through the fact that you're going to feel bad, you know you're going to get through it. And, actually, we used to laugh so, so much. I used to totter up the street on their arms to see if I could get a drink in me. 'Can one of us get a drink? I need a drink! I need more chemicals!' We used to have such fun. They used to take me shopping."
Hmm, now who does that sound like? Part of the move to London was to deal with the empty nest syndrome.
"I found it really quite hard. When Ade goes off to work or on tour, it used to be that we had a house full of teenagers and so you don't really notice. But when it's just you, you think, 'I want to be out in a restaurant with my mates.' "
The couple's middle daughter, Beattie, is in a comedy group of five young women called Lady Garden and lives in Clerkenwell with her younger sister, Freya.
Their oldest daughter, Ella, is living in Devon with her builder husband, and has started up a company specialising in open-framed cottages.
When the girls were young, they adored the Spice Girls and would beg to go to their concerts: "They were so lovely on stage and all these tiny girls would be looking up at them, and they were always so kind and unaggressive and so beautiful to them."
So when Saunders's agent asked her if it was OK that she'd put her forward to producer Judith Kramer (Mamma Mia!) to write the story and script for the Spice Girls musical, the response was:
"'Ring her up now and tell her not only do I want to do it, I have to do it. I have to do that musical.' And so I got the job."
The musical is likely to be unveiled next autumn, but in the meantime we have another story of an (albeit rather older) girls' friendship to look forward to, one that we Ab Fab fans really, really want to see. Welcome back, Eddy and Patsy.
Absolutely Fabulous in on BBC1 at 10pm on Christmas Day