Polpo, 41 Beak Street, London W1F

What's the secret of a successful restaurant? Is there a code it's possible to crack or is it completely unpredictable? As someone who has been reviewing restaurants for seven years, I'm tempted to say that no one knows anything. That's the same conclusion William Goldman came to in Adventures in the Screen Trade, his celebrated book about Hollywood. Like the film industry, the restaurant business is a place for gamblers. If you win, you can win big, but the majority of the players lose their shirts – and, according to Harden's, there were some 64 noteworthy closures in the capital last year.

One of these was Aperitivo, a modest establishment on London's Beak Street that specialised in Italian tapas. To date, this culinary trend has failed to take off. Londoners can't get enough of Spanish tapas and the Hart brothers (Sam and Eddie) have put themselves on the map by capitalising on this phenomenon with Fino, Barrafina and Quo Vadis. But Italian tapas? It sounds vaguely inauthentic, like something dreamt up by the marketing department of Pizza Hut. If people want fast Italian food, they're perfectly happy with pizza, thank you very much.

In light of this, the decision to open another Italian tapas restaurant in exactly the same space seems like madness. Surely, this cuisine has been consigned to the waste disposal unit of history?Actually, no.

Polpo is the dreamchild of Russell Norman, who cut his teeth at Caprice Holdings. Having worked at a number of restaurants in that group, he understands how to pitch a new restaurant. Yes, you've got to have a decent chef – and he has that in the form of Tom Oldroyd, who used to work at Bocca di Lupo on Archer Street.

It's also important to get the décor right, and he's nailed that, too. Polpo has a rustic, cheap-as-chips feel, with a black-and-white tiled floor and exposed brick walls. Anyone poking their head around the door to take a look will instantly know they're not going to get fleeced in here. ("A very comfortable, very relaxed, downtown New York kind of a feel," says Russell.)

More importantly, he's got the marketing spiel right. He doesn't describe the food as "tapas". Indeed, when I asked the barman whether that's what they were serving, he looked shocked and said, "We don't use that word." No, the small, reasonably-priced plates of food on offer at Polpo are "cicheti". Polpo is not a "tapas bar", either, but a "bacari" (which, funnily enough, is the Italian word for "tapas bar"). Above all, this isn't "Italian" food. It's "Venetian".

To those outside the restaurant business, this may sound like splitting hairs, but Norman knows that getting this sort of detail right is the difference between success and appearing on the Harden's casualty list.

He claims to have been "inspired" by numerous trips to Venice since he was a little boy – but that's all part of the spiel, obviously. The point is, by making his Italian tapas very geographically specific – and by using all the proper Italian words – he has created an air of authenticity around his new restaurant. It seems like a labour of love, rather than an attempt to carve out a niche in London's cut-throat culinary trade. It has the feel of something new, too, an undiscovered cuisine, rather than a rehash of an old one. And novelty always sells.

I popped in on a Monday lunchtime and it was surprisingly full, given that it can seat a total of 65 people. I opted for a place at the bar, which suited me, as I was flying solo. After admonishing me for using the word "tapas", the barman made amends by making a delicious Spritz – a Venetian spritzer with a dash of Aperol and a large green olive. "You won't be able to stop drinking these," he said as he handed it to me – and he wasn't wrong, particularly as they're priced at £4.

With the barman's advice, I ordered a selection of dishes, including a potato and Parmesan croquette (£1.20), chopped chicken liver (£1.20), pizzetta Bianca (£4), pork belly, radicchio and hazelnuts (£5.50) and, to finish, ciambella and chocolate (£3.50). The croquette was a little bit ordinaire, but the chicken liver on crostini was excellent, as was the pork belly and the ciambella (ring cake), which was drenched in chocolate sauce.

But surely the most impressive thing was how quickly all the plates came out of the kitchen. I arrived at 12.45pm and was wiping the final crumb of ciambella off my lips at 1.25pm. Russell Norman said he had no plans to turn this into a chain, but I wouldn't be surprised if we see several more Polpos springing up over the next five years. Perhaps someone does know something, after all.

16/20

Scores: 1-9 stay home and cook, 10-11 needs help, 12 ok, 13 pleasant enough, 14 good, 15 very good, 16 capable of greatness, 17 special, can't wait to go back, 18 highly honourable, 19 unique and memorable, 20 as good as it gets

Polpo, 41 Beak Street, London W1F, tel: 020 7734 4479. Lunch and dinner, Monday to Saturday. Total cost of food for one, £23.50

Second helpings: More tapas-style treats

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