I've had my eye on Oliver Peyton for a while. The Sligo-born entrepreneur who keeps opening hip restaurants in Britain as if they were, er, going out of fashion, has a novel approach to selling champagne. He keeps prices irresistibly low. (Roederer Brut Premier £28 last year. Taittinger this year £30. Now do you believe me?). People drink lots. I mean, oceans - 60,000 bottles a year, making him one of the biggest retailers of champagne in the world. At Isola, Peyton's new place in Knightsbridge, his latest trick is to serve 63 very good wines by the glass. We'd be mad not to sit up and take notice.
Of the five restaurants in his expanding empire - the Atlantic Bar and Grill, Coast, Mash in London, Mash & Air in Manchester - Isola is both the swankiest and the most serious. "This is a temple to food and wine," he said, as we clambered through raw concrete and showers of welding sparks a couple of weeks ago. "Customers understand so much more than they did a year ago. People will come for a full-on foodie experience." In print that sounds pretentious, but in person Oliver Peyton pours out his aspirations engagingly, with a large measure of Irish humour.
His intention, with Isola, is to create a new kind of power-dining room in a monumental building that will stand the test of time - "a cross between Albert Speer and modernity, something in that neighbourhood," he grins. But it will not be full of suits.
"I hate and despise poncey restaurants. It's often forgotten that an awful lot of rich people in London don't wear suits and ties. I have a friend who earns £1.4 million a year and he looks like a builder."
So, a restaurant which looks solidly handsome, in marble, parquet and steel, but which feels relaxed. Dedicated diners will head upstairs to a vast room offering intimacy against the odds, with booths on different levels upholstered in red leather by the people who fashion Ferrari carseats. Top French chef Bruno Loubet has been hired to do wondrous things with the purest Italian produce. "The whole deal here is Italian," Oliver Peyton says enthusiastically. "Italian food done in a way that hasn't been seen in England before."
Intriguing. But if, like me, you feel impatient to hop all over that wine list, you might be as well off in the Osteria downstairs. Here, settled more casually on black leather settees, customers can order food and wine as the mood takes them. That seems just perfect, given Peyton's bold approach to quality wines by the glass. "I wanted to have a very big Italian list because that's not being done widely in the UK," he says.
Isola's young sommelier, Federico Graziani, has cherry-picked from 20 importers to build a formidable all-Italian list. But it's the by-the-glass selection that excites him most. "It's the dream of every sommelier to serve a different wine with every dish," he says. In his last posting, Marchesi, he poured about 30 wines by the glass. Here, the choice is more than double that, with the nitrogen-based Cruvinet system promising to keep opened bottles fresh for up to five weeks.
What's on offer? Everything, from a tasting sample of a straightforward young Orvieto Classico at £2.10 to a full glass of Castello di Ama 1995 at a heartstopping £37.50. On average, full glasses cost £6 to £7 for whites (such as the wonderful Pieropan Soave Classico), and £8 to £9 for splendid reds (such as Selvapiana Chianti Rufina Riserva 1993 (see below) or Castello di Brolio's Casalferro 1995, or Aldo Conterno's magisterial Barbera d'Alba 1997). All 63 wines are available both in a 7.5cl tasting sample and in 17.5cl glass. Antinori Tignanello 1995, Allegrini La Poja 1993, Elio Altare Barolo "La Morra" 1994 . . . these are just a few of the items that might help you develop a thirst.
In fact, wine-lovers may decide to work through a full tasting selection. Federico Graziani has assembled five - each offering five tasting samples on a particular theme. Sample prices for this tempting exercise: Italian Varieties £14.60, Supertuscans £29.20, Gourmet £46.30. Wow.
Isola's entire list, encompassing some 300 wines and tens of grappas, cognacs and armagnacs, is a joy to read. And, as you might expect from bubbly Mr Peyton, champagne hasn't been neglected - there are 14, starting with Taittinger Brut NV at £35 (not bad, considering this is smart-new-restaurant-Knightsbridge), and working up through all the beauties to Krug Clos du Mesnil at £310. If you're drinking by the glass, you'll have to choose between Taittinger at £7.50 and Salon Le Mesnil 1988 - desperately grand - at £19.
Does it matter all that much what Isola is at? More than you might think, because of the influence pace-setting Peyton is likely to have on the restaurant scene. First in London.
"There will only be a couple of significant restaurant groups in the long term," he says, "and I want to be in there, big time. This year our turnover is £25 million. Next year it will be £35 million - and that's from a standing start in just five years."
Dublin is in the picture too. As is widely known, Oliver Peyton is planning, in conjunction with London's Groucho Club, Paul McGuinness and others, to give Dublin a similar club-type restaurant with rooms. "My top priority at the moment is to open in Dublin," he says - and he means business. I'll be surprised if he doesn't deliver an almighty kick in the vitals to Irish wine lists.
Isola, 145 Knightsbridge, London SW1; 0044 207 8381044. Open daily noon-3 p.m., 6 p.m. midnight (10.30 p.m. on Sundays). Osteria, downstairs; 0044 207 8381055. Open daily noon-midnight (10.30 p.m. on Sundays).