City lunchers have had to re-think their priorities lately. Gone is a three-course blow-out at the Mercer, with the throw-caution-to-the-wind bottle of Chateauneuf. A new realism is abroad. It's saying, You, my lad, will be lunching at Strada or Wagamama or Yo! Sushi for the immediate future. So why is everyone going to the Maze Grill?

It's Gordon Ramsay's new place, or, more precisely, the new kingdom of Jason Atherton, executive chef at Maze in Grosvenor Square, which picked up a dozen awards (and a Michelin star) in its first 18 months. Atherton offered the world small "tasting dishes", immaculately cooked on a robata charcoal grill, and costing £3-£11. You might assume similar cheapo options will be available at the new Grill, with its down-to-earth promise of seared meat. You'd be wrong. The Grill is a killing combination of cool simplicity and ruinous extravagance. It extends an elegant finger to the concept of going easy on the protein, the carbs or the cash.

It's a long narrow room like a glamorous train carriage, done up in muted hues of pale green, stone, putty, mushroom. The ceiling features metallic roundels like the acoustic baffles that hang from the ceiling in the Albert Hall, and the tables are round, many of them inside half-circle banquettes. It's easy to feel you're eating inside a CD collection. My date, Isobel, cast a knowing eye at the lunchers. "Lots of hedge fund managers," she said. "You can tell them from the bankers because they never wear ties."

Danny, our charming Dutch waiter, brought along the raw cuts of steak that form the restaurant's raison d'être. They were wrapped in a flannel, like a bad-taste Damien Hirst maquette. Let's see. You could have Casterbridge grain-fed steak, aged for 21 days, Hereford grass-fed steak, Aberdeen Angus grass-fed, Creekstone prime USDA corn-fed and Wagyu "9th Grade" corn-and-beer-fed steak. Oh, and the Indian Sacred Ox "10th Grade" steak fed with cornflakes and garam masala – OK, I made that up, but I'm bored these days with the stats about long-hung beef and the provenance of the cow. All I wanted to know were the prices of the Creekstone and Wagyu steaks. The former is £35-£40, since you ask, while the latter costs (deep breath) £110. A hundred and 10 quid?? What do they massage the cow with to justify the price? Isotopes of uranium?

Lunch, when it came, was lovely. Isobel's calves' liver was as well-done as she wanted (she has a Girl Thing about not seeing traces of pink in the membranes) and meltingly tender on its duvet of mustard mash. My "pigs on toast" was trotter-meat pâté served on toast with rocket and Parmesan: very nubbly and dark and masculine, like eating woodland roots. The salt and pepper squid was lightly battered and delicious, until the taste was murdered by the garnish of raw chilli but, really, I should've seen that coming.

What can I say about my steak? I chose the grass-fed (here we go again) 12-ounce Hereford rib-eye; it was dreamily smoky and flavoursome, its gigantic bone sticking out like a frying pan handle, its attendant roast head of garlic irresistible. Among a list of sauces I found one called, redundantly, "Steak". Ask for it, and your waiter will perform a little TV-chef pirouette and make it in front of you, assembling it from tomato fondant, molasses, brown sugar, rosemary, thyme, parsley, garlic, salt and Tabasco. Very nice it was too, though surprisingly close to the smoky barbecue sauce you can buy in squeezy bottles ...

Isobel's Gloucester Old Spot pork chop was porky and finely textured with no speck of dryness; she admired the way they'd served apple sauce as a halved apple oven-baked with sugar and star anise, until its flesh turned to mush. Washed down with a syrupy Portuguese Cedro do Noval, these were both wonders of meatiness served on chunky wood platters.

The puddings were pretty wondrous too. The Eton mess was a formal structure of meringue wheels sandwiching strawberries and raspberries, with a coulis of both fruits poured over the top. It was the least messy Eton mess in the world; you had to smash it to bits yourself, and very yummy it was. My apple cider trifle was a cocktail glass of green jelly covered by vanilla custard sprinkled with chunks of cider granita, as pleasing to the eye as to the ecstatic taste-buds.

It came with a brace of little cakes called financiers. Foolish, really, the innocent joy one can derive from wolfing down a couple of City moguls. I hope they won't be the only people who can afford to enjoy Mr Atherton's pungently appealing cooking.

Maze Grill, 10-13 Grosvenor Square, London W1 (020-7495 2211)

Food 4 stars
Ambience 3 stars
Service 4 stars

Around £120 for two, with wine

Tipping policy

“A12.5 per cent discretionary service charge is added to all bills. Gordon Ramsay restaurants operate atronc [or kitty] system and the service charge is shared among the staff at the discretion of the tronc master, whois independent of the restaurant management”

Side Orders: Where's the beef?
By Madeleine Lim

Champany Inn
This Michelin-starred restaurant with rooms serves a selection of Scotland's finest steaks, selected from prime Aberdeenshire cattle.
Linlithgow, West Lothian (01506 834532)

Blackhouse Grill
Provenance is all at this Chester steakhouse: try a well-priced £13 rump steak or break the bank with a £50 kobe fillet that has been massaged and fed with beer.
Newgate House, Newgate St, Chester (01244 400507)

Gaucho Grill
Superb Argentinean steaks at this glamorous Manchester restaurant; try the churrasco de cuadril (rump steak), which has been marinated and spiral-cut.
2a St Mary's St, Manchester (0161-833 4333)

The Albemarle
The steaks at Mark Hix's revamped restaurant at Brown's Hotel are served on the bone, which adds succulence and depth to the flavour.
Brown's Hotel, Albemarle Street, London W1 (020-7493 6020)