'The River Café's location is unique'

"We both knew we wanted to cook rustic, homely Italian food. Rose had been living in Italy, and Richard's mother, Dada, was Italian and, I tell you, she really knew how to cook."

Dada Rogers was a formidable woman. "When I first met Richard, I was already very interested in cooking. But when I met his mother she was just inspirational. When Rose and I first opened the restaurant, she would come and say things like: 'Too much oil' and 'Don't overdo the garlic'.

"In fact, the last thing she ever said to me as she was on her deathbed was: 'Remember two things in life, Ruthie - always use face cream and never overherb fish.' She was amazing."

Then there is the River Café quiz - the £200-a-table charity event, organised by Gill Hornby, wife of novelist Robert Harris. Those who pay to take part include Mark Bolland, Piers Morgan, Francis Wheen and Stephen Fry. It has become a key fixture of the social calendar for the city's intelligentsia as well as a showcase for the Rogers's far-reaching network of influential friends. For the Rogers are a bit of a power couple.

Before Ruth, now58, met her husband, she was just a quiet country girl from upstate New York. "I grew up in Woodstock," she says. "It was great, full of music. Bob Dylan moved there for a bit. It was pretty cool."

Her own mother wasn't a fantastic cook although her Hungarian grandmother made a mean goulash. "I didn't start out a natural cook myself," she says. "It just grew over the years."

She was 21 when she met Rogers a party. "It was pretty immediate for me," says Ruth. But Rogers was married with three children, all boys. "Of course it was difficult but it was a long time ago. We've been married over 30 years."

They went on to have two boys of their own and the extended family sorted itself out pretty effectively. "Everyone goes backwards and forwards," she says. "We all see each other as much as possible." But isn't she always cooking? She tells me she cooks at home - a large townhouse in Chelsea - nearly all the time. "I had 40 for Thanksgiving," she says.

When you take into account their wellconnected friends - both are renowned New Labourites - and their vast extended family, their house must be constantly buzzing. "Well, now we are getting older, we try to lead a quieter life," she says. But her husband, who has built some of the world's most iconic buildings - the Lloyd's building in London, Madrid's new airport, the Pompidou centre in Paris - still spends one day a week with Mayor Ken Livingstone, discussing the architecture of the Olympics.

Does Ruth like Livingstone? "When it comes to what he has done for London, then yes, I think he has done good things. I totally agree with the congestion charge. We don't have a car, no. I cycle everywhere."

Does she get involved with her husband's projects. "I'm his wife! I know what he's doing. He knows what I'm doing. We are very close, we have had a long marriage." Their proximity has probably helped. "We are both very invested in being here, being near each other," she says.

Is this why Ruth Rogers has not branched out further? Why are they not more like Gordon Ramsay or Jamie Oliver or Hugh Fearnley-Whittingstall, both of whom began their culinary lives at the River Café? "Ah well," says Ruth, "Jamie and Hugh don't have their own restaurants!

"We hired Jamie because he was so cute. He still is cute but he doesn't have his own place. Rose and I cook here every day. That's what we have always wanted to do, so we don't have a lot of time for anything else." But was Jamie any good? "Yes, he was good. You could see he wanted to learn. He was so enthusiastic."

What about Hugh? He was let go by Rogers and Gray. "Hugh came here virtually straight out of Oxford and he had a reputation for being a very good cakemaker. We hired him and he did desserts, but, to be honest, we need chefs who can do everything. We don't have designated dessert chefs." But was he any good? "Yes, he was, and he's gone on to do great things, but he made a lot of mess!"

Ruth says that she and Rose wouldn't mind doing more TV but that they don't want to go down the Gordon Ramsay route. "I don't think Gordon can possibly find the time to cook," she says. "It all turns into a bit of a circus really. " The rise of the River Café reflects the rise in the public's obsession with good food.

"I hope we've been a part of that," says Ruth. "When we first started and we were always banging on about seasonal food, I think people didn't really know what we were talking about. It was actuallynot that easy to get garlic sometimes. Now you can get most of the ingredients we use absolutely everywhere."

Their new cook books - which are divided into four categories - pasta, vegetables, puddings and fish - are slimmed down, easier versions of recipes in their other books.

"We just thought it would be great if you were going to the supermarket or you were travelling abroad. Also, they are a good gift for kids going off to college. The recipes aren't difficult at all."

But Ruth says the big difference is that people eat out more. "It used to be a really big deal, a treat, but now it is part of people's everyday lives. They pop out for dinner. They bring their kids here on a Sunday. It's almost a traditional thing, coming here." I imagine she hopes it may continue for another 20 years, particularly now the restaurant's future is secure. "Absolutely!" she says.

And I'll bet that she and Rose Gray will still be here cooking up a storm if it does.

The River CafÈ Pocket Books (Ebury, £8.99 each).