Lunch with Supergrass
Eva Wiseman joins the Britpop band for home-made borscht and cocktails at home in Oxford

There are fewer things more endearing than a pop star, embarrassed. Gaz Coombes, the 31-year-old frontman of Britpop's last standing success is mortified to see me trip on a half-eaten mouse as I enter his sprawling Oxford home. Swiftly, chivalrously and tail-first, Gaz hurls it into the field next door, where three cows look up and gently defecate in unison.

Inside, lunch is imminent. Mick, the bass player, is doing starters, a beetroot borscht; Gaz is doing chilli lamb burgers, with mince from Finns, their local farm shop and 'a bit of a kick' (ie, trowels of chillis); Rob, the keyboardist, is doing ice cream; and the drummer, Danny, is on cocktails. Black Magics they're called, and he's following the recipe from a little hardback book. As Supergrass compare proteins, their PR and manager approach. 'We might just pop off to Asda,' says one, 'to get some polish-a-turd garnishes.' Looking anxiously at Mick's organic beetroots, the other asks, 'Can you just make sure they sound, you know, rock'n'roll enough?'

Supergrass entered the pop charts in 1995 with 'Alright', a jangling singalong that inspired Steven Spielberg to approach them with plans for a Monkees-style TV show (they turned him down) and boasted of their extreme youth. Thirteen years and six albums on, their teeth still gleam but now they're very, very grown-up.

With his partner Pearl Lowe, Danny Goffey is father to two sons and a baby daughter, Betty. For the last 12 years he's been stepdad too to Daisy, whose modelling career rocketed soon after she found out that her biological father was Gwen Stefani's husband, Bush frontman Gavin Rossdale. The Lowe-Goffeys have been tabloid fodder since, as part of the much-papped 'Primrose Hill set'; in 2005 they were rumoured to have taken part in a Jude Law wife-swap, and shared numerous good times with Kate Moss. Last summer Lowe published a memoir that detailed her battles with addiction, and the family's new, organic, healthful life in rural Hampshire away from party influences.

Mick Quinn has significantly fewer rock'n'roll credentials. He did appear in the papers however, when, last August, he fell out of a first-floor window, sleepwalking in France. He broke two vertebrae and smashed his heel. Today, he walks with a stick, but he's expected to make a full recovery. Their managers said falling out of a window was something they'd expect from anyone else in the band except Mick. 'If it had been Danny who fell,' Mick says, 'he'd probably have landed on someone else and walked away.' Rob Coombes, Gaz's older brother, officially joined Supergrass in 2002. He is a qualified astrophysicist, with his own telescope. And his last blog post (on Bob's Big Blog) charts his favourite festival toilets. Gaz's downstairs toilet is quite good. There's a pink plastic tiara on the cistern, evidence of his four-and-a-half-year-old daughter, whose Velcro star chart in the kitchen shows she's had an excellent week. Gaz's partner of 15 years, Jools, is pregnant again, and, as she slips away to let the band 'do their lunch ... thing', she apologises again for the mouse incident. 'We got one of Danny's cat's litter,' she says, 'and she's just been spayed, so she's been taking her anger out on nature.'

There's a lot of nature here. The Coombes residence is hidden down a tree-lined trail in a village just south of Oxford. There are rabbits and cows, the smell of woodsmoke, and a framed portrait of Elvis Presley behind the door. The blackboard above the sink reads, 'Empty woodshed. Buy Harpic'.

This is the house that Gaz and Rob grew up in. When their mum died Gaz was loath to let the house go, so two years ago moved his family up from Brighton. They plan to knock through the dining room and 'get rid of a bit of the childhood', but they're keeping the kitchen table. 'Because this table's seen some action,' says Gaz.

'The table fun all started quite innocently when we were kids with Scalextric and Subbuteo, and then as the years rolled on the booze came in, and then the various substances ... We've had some good times at this table. When our parents went away we used to have manic parties. About 10 years ago I stained the surface with black ink, which I spent hours trying to get rid of. It just wouldn't disappear. I got into a lot of trouble. Then, I tried to look for it the other day, and it's just ... worn away.'

Today they're going a little way towards recreating the table's most recent celebration. 'On New Year's day there were 15 of us,' says Gaz, 'critically hungover, but working on the cooking. We put on some Hendrix and got a real kitchen vibe going. I was very proud.'

Danny's pacing. He paces around the kitchen, and the dining table, and outside to the conservatory, and then back to the kitchen. He is fretting, mainly about the lack of Kahlua, an essential element of a Black Magic. Mick's girlfriend dashes home, winding around the classic cars in the driveway, to find the dregs of last night's White Russians and, when she returns, breathless, Danny relaxes. He shares the cocktails and tells a story about being given a matchbox of LSD by the singer in Blind Melon, who died of an overdose the following day. Supergrass took it just before joining Jamie Theakston on The O-Zone

After a brief skirmish over the music (eventually they settle on Television's first album) the cookery proper begins. Gaz massages the mince, Mick starts shaving his beetroots, and Rob talks me through the ice-cream plans. 'Instead of putting it in the freezer, I'm going to add liquid nitrogen,' he bubbles, 'I saw Heston Blumenthal - that guy with the glasses - do it on TV.' He produces an aluminium canister from his coolbag. 'I got it from a nice man called Nigel in Oxford University's cryogenics department.' Does it make the ice cream taste better? 'Don't know. But the main thing is that it looks cool, and I get to mess around for a bit.' Rob, the least famous of the band, has road-protester's hair, and a softly educational voice. With his rubber gloves on, he tests the liquid nitrogen, and recalls life before Supergrass. 'I was very into spectroscopy at college,' he says, 'splitting light from a star into a spectrum. You can learn a hell of a lot from one point of light in the sky.'

A small explosion happens by the fridge. I go to collect fallen blueberries, and admire Mick's borscht, now bubbling on the hob. His hands, and the sink, are both stained a fetching pink. Washing up is done as it appears, 'because Jools is up the duff and all that'. The kitchen is filled with steam and smells, and there's much excitable poking of arms and bellies. The band rarely cooks together - while touring they work on expanding their palates ('We fell in love with raw fish!') with little diversions for 'really disgusting cheeseburgers. They're worth it for that McDonald's afterglow.'

Gaz's chilli burgers are doused in mayonnaise, then eaten wildly. There's cream, for the borscht, and then the thrill of Rob's ice cream. He's been whisking milk, cream, egg whites and sugar together for almost an hour. He's in quite a lot of pain. It's all forgotten though when the liquid nitrogen appears. 'All food should be like this!' Rob says, as steam curls around his grin. The ice cream tastes delicious. And then, with the leftover nitrogen, we get to try freezing other things, like baby tomatoes, which crack in half, burn your tongue if, like me, you're foolish enough to try and eat them.

It's dark by the time we leave. I step around the little damp mouse spot on the porch. As we trundle up the drive, I look back to see the band silhouetted in the window. They're flinging frozen tomatoes around the kitchen, and mouthing the words to 'Marquee Moon'. Steven Spielberg's cheque-writing hand would be quivering.

Eva Wiseman, Observer Food Monthly - 30 March 2008