St John is in his heaven – or hell, dependent upon your taste. Here we have uncompromisingly British, and stripped down to the bone – such defiant unfanciness in accordance with the unassuming Georgian terraced building just around the corner from Smithfi

St John is in his heaven - or hell, dependent upon your taste. Here we have uncompromisingly British, and stripped down to the bone - such defiant unfanciness in accordance with the unassuming Georgian terraced building just around the corner from Smithfield.

Last year, to the consternation of its diehard admirers, the whole place closed for a six-week refurbishment. The bright white walls and ceiling were jollied up to the extent that they are now bright white, and wholly indistinguishable from before. The floor is hard and industrial, just as it always was.

The sole adornment is a plain wood Shaker hatrack. The chairs are dull, the refectory-style tables covered in paper cloths (white, need you ask) with no ornamentation. The stainless steel kitchen is open to view while the overhead pendants (white) have mirror-domed bulbs so as to illumine bugger all. If you come to dinner rest assured that it will be all white on the night. So heaven? Or hell?

This unique establishment has had a very loyal audience since it opened 15 years ago, but only recently has it been acquiring awards and a far wider recognition. This year it was given a Michelin star, which is astonishing, frankly. Not because the food does not merit it (it does, it actually merits two) but because the place is the very antithesis of what Michelin inspectors ritually go for: there is no decor, no trolley, no French cuisine, no rich and traditional sauces, no little frothy freebies - ravioli of this, cappuccino of that. Indeed, apart from air conditioning, there are no creature comforts whatever.

Restaurant magazine placed it at number 14 in the world, number two in Britain (after The Fat Duck) and number one in London. Crumbs.

Fergus Henderson is the famous chef - but in a good way: he is known for his cooking and not for flirting, bitching, profanity, ill-temper or advertising Sainsbury's. His concept is simple: "nose to tail eating", he calls it - although he murmurs of difficulties with lungs, and admits to being utterly trounced by the sphincter (other than that, though, he goes the whole hog).

Now I've got to be honest here - me, I'm not that gone on noses, you know - tails I can frankly take or leave. And here's the rub: whether or not you truly enjoy your meal here wholly depends upon whether the parts of always top quality animals on offer on the day in question happen to be those that you feel you can decently put into your mouth without the help of a rich sense of humour, a stiffish drink, or else for the sake of a bet.

Out of step with your average restaurant critic, I tend to prefer the central and outer parts of your cow, lamb or pig, while avoiding all extremities and any hint of innards.

So if you are a fan of nettle soup, crispy pig's skin, duck hearts, goat's curd, ox tongue, eels and kid faggots, then on the day I had lunch there, you were in for a treat (those faggots, they haunt me still... I just couldn't help wondering whose kid it was).

I was with a couple of Captains of Industry who lunch here once or twice a week (it inspires that level of devotion). These are the sort of chaps who affect never to notice such fripperies as decor, and here they affect not to notice its total and utter absence. One of them kicked off with white cabbage (to match the walls), the brown of the accompanying shrimp being the nearest this place is ever going to get to an explosion of colour. He loved it - happily dunking first-rate bread (there is an on-site bakery) into fine olive oil.

Plutocrat number two declined a starter on the grounds that he was dining that evening (probably here). I couldn't resist new season asparagus with hot butter: excellent, of course.

As to mains, one chum was going to go for braised rabbit with bacon and mustard, while the other was toying with snails, sausage and chickpeas. At that point, a special was scrawled on to the blackboard (which, and this shouldn't surprise you, is white). Halibut and chips.

The three-inch thick tranches they pounced upon had them in raptures (in that they nodded, once). And the chips! One so often hears of "the perfect chip" but here, truly, was it: large, utterly crunchy, blissfully golden - and then a detonation of soft and potato-flavoured potato within. My new potatoes also possessed this same rare quality: potatoeyness - it's as if you've never actually tasted one before.

And with them? Roast Middlewhite with braised Little Gem: fine and tender pork, not fatty, deeply flavoursome and extremely comforting. The lettuce had bits of carrot and bacon strewn into it, also highly gratifying. And here's something: le patron mange ici.

At the very next table, there was Fergus Henderson. Many might prefer le patron cuit ici, of course, but since the onset of Parkinson's some years ago, the boss tends to take a back seat.

The delightful waitress (they are all friendly and professional and dressed in, um - whites) brought us a decent Cotes du Roussillon at �24.15 - the sort of thing that shouldn't at all have gone with the two lads' halibut, but they never care about things like that (this is the attitude that got them where they are today). It was superb with my pork, though, so who can mind?

So far, then, so heavenly - then it got a bit hellish. Pudding: the white blackboard had come up with an apple crumble with a fine and proper custard, so one of the Masters of the Universe leapt on that, the one who was dining later (probably here) declining. I had a chocolate terrine with vanilla ice cream: this was sensational - just a thick slice of the cool and sticky, intensely chocolatey centre of a sachertorte, meaning you don't have to plough through the spongey bit. So where's the hell in any of this? Well, it wasn't the grub - it's just that three feet away on the counter dividing the restaurant from the open kitchen, a commis chef began to dismember a lamb. The whole thing. Chop chop. Skin skin. Slice slice. Oh yuck.

One of the chaps I was with said he hadn't noticed, the other rather liked it. One woman diner dropped everything and went up there for a close-up... so it's just me then, is it?

Later, the commis hauled out a bright blue first aid box and applied an elastoplast (not, obviously, to the lamb, which by now had simply gone to pieces). I latched on to the first aid box because of its bright blueness (colour!) - quite as welcome as the huge and sunshine yellow bucket (more colour!) lugged through the restaurant while all were still eating by a mop-wielding cleaner.

So all this extravagant unpretentiousness... well - if you love it, it's heaven, and if you honestly just can't bear it, it can be rather hellish.

Down in the gents, there's a Dyson Airblade - the genius's latest gizmo for drying your hands. The sign says to insert your hands and extract them slowly. So I inserted. It set up a roar like a brace of jet engines while sucking ferociously - and I can tell you, matey, those two hands of mine were extracted like greased bloody lightning. I think it was the thought of that poor kid and his faggots: they haunt me still...

o St John, 26 St John Street, EC1M 4AY

o Telephone 020-7251 0848

Food: Five stars

Service: Four stars

Decor: No stars

Open Mondays to Saturdays noon to 3pm, 6pm to 11pm Sundays 1pm to 3pm

Cost: �110 for two with wine