St John's Tavern 91 Junction Rd, London N19

"I have dined in the world's finest establishments," Sergeant Bilko tells a chef, in an episode of The Phil Silvers Show. "When I say 'dined'... I thought I was dining. But since I ate at your restaurant, I realise that I was merely grazing, like an animal."

I can never sit down in the main restaurant at St John's Tavern without this remark (a cynical bid to steal the man's secret recipe) coming to mind. This dramatic dining-room, with its open fireplace, large sofas, and walls hung with highly distinctive paintings by owner Nic Sharpe, exudes that contagious attraction of a place that knows exactly what it is. The décor isn't dissimilar to that of the legendary Bar Pastis in Barcelona. Sitting here in London N19, you could be anywhere in the world – one of the reasons that St John's (a few miles north of most other smart restaurants in the capital) has managed to persuade discerning London gastronomes to make the short journey away from their heartland in Mayfair and the West End.

And then there's the food. I could quite happily spend the rest of my life eating nothing but the prawn bisque at St John's: seasoned more adventurously than you might expect, with strong notes of lemon juice and Tabasco. Head chef Karl Omell has dedicated himself to producing fresh and unpretentious dishes using, where possible, the whole of the animal, sourced from carefully selected, exclusive suppliers. My wife Emma's starter, jellied pig's head (served with caramelised onions, mustard and toast), is a delicate, inventive combination whose alarmingly robust title many restaurant owners might be tempted to disguise by listing it in French.

The ambitious menu includes a wide range of fish and vegetarian choices. (An equally impressive selection is served in the light, spacious bar adjoining the restaurant.) My main course of dab is filleted, simply seasoned with salt and pepper and lightly grilled, served with sauté potatoes and spinach. Having developed a chronic aversion to words such as succulent, moist and flavoursome, I have to restrict myself to a more general adjective: stunning. Presented immaculately, as here, the dab has the delicate flavour of a tiny sole.

The staff at St John's are friendly without being intrusive: a more traditional establishment, especially if French, would have lectured me on the sin of accompanying fish with a red wine of the heavy bomb load like the Vacqueyras 2007. (The slightly less combative Portuguese Douro, Vinha da Palestra 2008, is an impressive full-bodied alternative, and £9 cheaper at £20 a bottle. House wines start at around £15.)

Emma chooses venison meatballs for her main. Perfectly seasoned with pepper, bay leaves and traces of juniper and fennel, in an onion sauce and presented with mashed potato and curly kale, it is typically bold, original and delicious.

Among the many things I really love about St John's is the restaurant's commitment to sourcing interesting varieties of cheese. Some celebrated London institutions don't offer it at all. To many chefs, especially the ones who have to invest valuable time promoting their own public image, the business of finding and curating a varied cheese collection is, put simply, just not worth the trouble. Here, it's regarded not as a chore but a labour of love. St John's Tavern has a wide and typically imaginative range both of domestic cheeses such as Barkham Blue, produced in Wokingham in Berkshire, and a choice of unpasteurised French cheeses such as Munster and Maroilles, whose description on the menu as "pungent" proves to be no casual boast.

Everything in food is subjective, and if you're looking for an excursion to the kind of fashionably minimalist establishment where you can be sure of finding a sorbet that tastes exactly like wildebeest, St John's is not necessarily for you. There are probably things that could be improved at this extraordinary restaurant: it's just that, for the moment, I can't identify any, beyond the fact that I can't afford to go there every day. As nothing in life is perfect, I could pretend that the score below has been rounded up from the nearest decimal point. The truth is that I can't think of a more accurate way of quantifying a ticket to heaven.

10/10

Scores: 1-3 stay home and cook, 4 needs help, 5 does the job, 6 flashes of promise, 7 good, 8 special, can't wait to go back, 9-10 as good as it gets

St John's Tavern 91 Junction Rd, London N19, tel: 020 7272 1587 Lunch, Mon-Thurs; lunch and dinner, Fri-Sun. About £30 per person for three courses, including wine

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Reviews extracted from 'Harden's London and UK Restaurant Guides 2011' www.hardens.com