For me, the restaurant that best fits this bill is Roka, a fantastic Japanese fusion restaurant on Charlotte Street, north of Oxford Street. It's the sister of Zuma in Knightsbridge. I used to work in that area and went to Zuma a few times, so when Roka opened 10 paces from my office it was great - I could just pop out for an hour's lunch when I needed to.
The menu is so varied and unusual that it needs to be explored as a team, and the spectacular dishes that arrive rarely cater for one.
There's always something new to discover, but I can never resist the salmon teriyaki. I'm mad on fish, and have been known to order two in a sitting (I could probably go through a whole shoal while I'm there). I'd also recommend the tuna loin and the edamame, which are delicious. They do brilliant fruit cocktails if you don't want alcohol at lunch and are bored of mineral water, but they have really good wines and Japanese beers too.
The service is impeccable - they remember your name if you've been before and you're always welcomed with a smile; the atmosphere is always busy and buzzy, but you can still hear what your lunch partner is saying across the table; and in the summer, the windows open up and the wooden tables spill on to the pavement.
Sometimes, it's impossible not to settle down for another hour or so with a lychee cocktail, so I suppose the long-lunch legend is a reality.
37 Charlotte Street, London W1T 1RR, 020 7580 6464, www.rokarestaurant.com
'Robata' set lunch £25.00
Salmon teriyaki £12.60
Tuna loin £15.90
Fruit cocktail £8.90
Sarah Gold is managing partner of advertising agency CHI & Partners.