St John
Address: 26 St John Street, London EC1
Telephone:020 7251 0848
Meal For Two, including wine and service: £110

If ever I doubted the degree to which my emotional responses are governed by what I eat, I needed only to examine my feelings about the roast bone marrow with sourdough toast that I was served at St John. I didn't feel excited or anticipatory. I didn't feel happy. I felt affection. We had been through a lot together, this dish and I, and it was a pleasure to see it again. It is, to my mind, close to a perfect plateful of food: four sawn-off pieces of hard roasted beef bone. You take a pick and scoop around to release the hot jellied marrow which you spread on the toast, left just a little too long under the grill to create a few burnt, earthy places. Sprinkle with some sel gris, and eat. On the side of the plate is a salad of roughly chopped parsley leaves, dressed in something sharp to cut through the richness. On the plate it looks like sculpture. It eats, however, like something straight out of the nursery.

As I ate this it occurred to me that, while I had used St John as a reference point for many other reviews, I have never written about St John itself. Though I do so now, there's little point regarding this as a review - I would struggle to achieve any sort of objectivity. Think of it instead as a love letter, one written long into the relationship and not in the first blush of arousal.

From the moment self-trained chef Fergus Henderson opened his restaurant in 1994, in a converted smokehouse in Clerkenwell, St John became a cult. With its whitewashed walls and hard surfaces, it has been described as abattoir chic on account of the meaty, offal-orientated dishes Henderson likes to serve. In truth, it is just an old-fashioned kind of modernism of the sort the true pre-Second World War modernists would have recognised - that withdrawal back to essentials forcing concentration on to the plate. There is no flummery here. It is worth knowing that Henderson trained as an architect: while what comes out of his kitchen appeals to the appetite, there is also something uncluttered about his plates. Some chefs create dishes which look like they have been styled by a battalion of interior designers; Henderson looks for utility.

So if a dish reads 'veal chop, chicory and anchovy', as my companion's did, that is what you get. Would you want to hit me if I said it was not just about the ingredients, but the spaces in between? I can take it. A lot has been made about the overt Britishness of Henderson's cookery, and there's no doubt that, with his interest in ox tongue and brown shrimps and tripe, this is indeed a British restaurant. But it is also inspired, I think, by a sensibility found on the other side of the Channel. That impeccable veal chop, butchered thick and with a fine char and a ballast of fat, alongside the leaves of well-dressed chicory, looked in its simplicity distinctly Italian. Other dishes, like a boozy hare broth - essentially an unclarified consomme - loaded with mushrooms, strike me as being the British equivalent of French paysanne food. (The wine list is notable for being entirely French.)

And then there are the more obstinate dishes, the ones that seem to be trying to get in your face for shock value: the crispy pig's tails, the roast ox heart with celeriac. Or the main course I had, the salty charred chitterlings with swede. Chitterlings are pig's intestines, first braised and then grilled and served as a coil of themselves with a dollop of mustard, and tasting densely of the farmyard. I understand fully that some of this makes eating here look less like dinner and more like a contact sport. It is overtly male. But it is also serious in its intent, and I like it for that.

I am, I hope, enough of a lover to recognise its faults. There are times when the ever-changing menu appears to become a parody of itself; when you sit down and, in the long parade of inner wobbly animal bits, find much to admire but little you actually want for dinner. Brutally, I have to say that I think the kitchen became less consistent after Henderson was forced to retire from cooking on service due to being diagnoses with Parkinson's disease. Sometimes sauces would be a little thin, dishes ill executed.

But even at its worst, St John is so much better, so much more itself, than many other places. Only St John would serve a whole plate of freshly baked madeleines as dessert. Or a honey mousse with prunes that tastes more like honey-laced chantilly. Or an Eccles cake with crumbly Lancashire cheese on the side. I have eaten some of my favourite meals at St John, including a whole suckling pig between 15 of us. Langoustines and mayo to start. Lemon posset to finish. Pig in between. That's the thing about truly great restaurants. They give you memories. And that's what St John does for me.

· jay.rayner@observer.co.uk. Word of Mouth, The Observer's food blog, is at observer.co.uk/foodblog