Eating Out: Sorting the tack from the taco

FINA ESTAMPA; 150 Tooley Street, London SE1 2TU. Tel: 0171 403 1342. Open Monday to Saturday noon to 3pm and 6.30 to 10.30pm. Average price per person pounds 15 (without wine). All major credit cards accepted

A few years ago I went on holiday to Baja California, the long peninsula in north-west Mexico that defines the fish-rich Sea of Cortes in the finger-shaped gulf between itself and the mainland. Plans for a blissful fortnight fishing and diving my way from Cabo St Lucas in the south to Tijuana in the north were suddenly curtailed when I swerved my hire-car to avoid a cow that appeared suddenly from behind a rock beside the road. After a series of spectacular flick flacks through the cacti my car settled roof down in the desert, and I hauled myself out of the driver's window to find a substantial shard of its cracked glass wedged deeply in my arm.

After one night in hospital I spent a week in a cheap beachside hotel in the sleepy town of Loreto, doing very little except drinking margaritas, smoking Kent and reading Carl Hiaasen. This trinity of consolatory pastimes was a great comfort, but the food was an even bigger one.

Fish tacos were the thing: fresh fillets of snapper or dorado, or squid or enormous prawns, deep fried in a beer batter, laid out on a soft tortilla, and smothered with shiny guacamole the consistency of double cream. Chopped coriander leaves and a choice of fresh chilli salsas ranging from wickedly hot to don't-even-think-about-it were always on hand. I can think of no better combination as sustenance for a rest cure.

At irregular intervals since that marred but memorable holiday I have hankered after the taste of Mexico. But the experience, predating my trip, of cavernous basements blasting out salsa or heavy rock, and serving pseudo- Latin fast food in dimly lit booths, has generally dissuaded me from attempts to rediscover that lost culinary chord this side of the Atlantic - except once in a while in the privacy of my own kitchen.

Last week I happened on my Baja handbook in the bookshelf and the craving came over me once again. Could it really be possible that of the 50 or so restaurants in the capital claiming to serve Mexican food, not one of them could do me a decent taco? So I called the Mexican Embassy and asked if there was anywhere they could recommend - for the food. The press attache told me to go to Si Senor (2 St Anne's Court, London W1, tel: 0171 494 4632), which she said was the only London restaurant actually run by Mexicans. The food was excellent, she told me.

I only had to walk into the place to realise that her recommendation was motivated by something other than good diplomatic relations. The decor smacked of every cliche in the DIY Authentic Mexican Atmosphere Handbook (in which the word "authentic" is used in the modern sense - to mean its exact opposite). If I tell you that there were hundreds of dolls in sombreros hanging from the ceiling, perhaps you can imagine the rest.

Had the food been anything other than mind-blowingly average proto-Mexican "classics", I would have devoted the rest of this article to describing it for you. All I will say is that the chimi-changas are better than the fajitas; the deep-fried, cheese-stuffed jalapenos are passable companions to a frozen margarita that has neither enough lime nor enough tequila, and melts too quickly; and the ceviche is an absolute travesty (tainted fish and bottled chilli sauce served up in a tall glass clearly intended for a knickerbocker glory). I'm sure this is not the worst Mexican food in London (many years ago I spent a grim evening at Break for the Border), but I despair to think that it may conceivably be the best.

My mission to recapture the flavours of Baja back in Blighty has been put on hold. But I was keen to salvage something from the wreckage (just as I had back in Baja), so when a friend, to whom I relayed the tale of my Mexican mishap, told me that the only decent South American food she had had in London was at the Peru-vian restaurant Fina Estampa, I went like a shot.

What a pleasure it was to walk into a place that actually felt like a family-run restaurant (as opposed to a badly conceived theme eaterie in which the prevailing theme is "fleece the undiscerning"). Three of us arrived for dinner there, and we all kicked off with pisco sours. Pisco is a kind of Peruvian grappa, on the rough side, but fantastically refreshing when blended with crushed ice, lime juice and a little sugar, and topped with a dash of Angostura bitters and a sprinkling of cinnamon. These knocked the ponchos off Si Senor's feeble margaritas.

But it was the food that reminded me what a huge difference there is between restaurants designed to make big money, and those conceived simply to generate a livelihood for chef proprietors (in this case an English husband-Peruvian wife team) who feel they have a few culinary secrets they would like to share with anyone curious enough to give them a tasting.

And so, at Fina Estampa, the dishes arrive like whispered gossip, confided by good- natured waiters with a twinkle that says, "you may not have seen anything quite like this before, but believe me, you'll like it". For example my starter, called papa a la huancina, and in truth little more than a potato salad (potatoes are, of course, big in Peru), was made by a sensational sauce; when I say it looked like a curdled mayonnaise and tasted slightly cheesey, please don't be put off. Those are just the nearest points of reference I can give you for such an unfamiliar, but truly ambrosial, concoction.

I won't give away too many more of the menu's secrets, except to say that the ceviche restores honour to the name so defiled by my Mexican experience, and enthusiastic carnivores would be well to order lomo saltado as a main course.

I liked everything I tasted, and left feeling there was plenty more on this menu I'd be keen to have a go at - which, if you think about it, is more or less the best feeling you can have when leaving a restaurant.

Hugh Fearnley-Whittingstall will be hosting a Wild Food Cookery Week on the Earl of Cawdor's Scottish estate in August. Call 01667 404666 for a brochure.