The expressions of warm, hugsy love-sodden emotion are hard to miss at the Bonnington Cafe in south London's Vauxhall. Awaiting us, in our little corner, is a slip of paper which reads: 'This table lovingly reserved for ...' and then the name of the booking. Scribbled up on the blackboard, the only menu in the place, is the description of tonight's dessert and then the words '... lovingly garnished with edible flowers'. The casual on-looker would assume this to be a joint fair drenched in the milk of human kindness. Which is all very odd because, having just had to eat the food, I can only conclude the chef really bloody hates me.

Let's be clear: I have form when it comes to the sort of vegetarian malarkey that the Bonnington trades in. I have said very rude things about vegetarians over the years, and they have said very rude things back to me. I find their whining about the lack of choice offered to them in mainstream restaurants tiresome.

Restaurants are not part of social services. They are businesses and you can be certain that, if chefs really thought they were missing an opportunity to turn a dime, the non-meat eaters would be catered for. Vegetarians have simply made a lifestyle choice, one they are entitled to, but they have no right to demand special treatment. And then, of course, there is the food. But we'll come back to that.

What I can't take issue with - what no reasonable person could find fault with - is the Bonnington Cafe itself. It is a complete anachronism and all the more wonderful for that. It began back in the 1970s as a communal kitchen serving the squats that made up the local neighbourhood in Vauxhall Grove, a pretty street of Victorian red bricks hard by Vauxhall Bridge. 'In those days the houses were in a very bad state and did not have cooking facilities,' says Margarete Baur, the longest standing member of the community group which runs it. 'But one by one the houses were done up, they acquired kitchens and the cafe had to find a new way.'

At first it was a very ad hoc affair. Someone said they would cook for an evening, and the locals were invited to pop in for dinner if they didn't fancy cooking for themselves. Eventually it resulted in the situation today where a rota of cooks each take a different night, paying a rental to cover upkeep of the cafe and holding on to whatever cash they make. Aspiring cooks can join the rota at the monthly meeting by agreeing to work with one of the other members to prove they know what they're doing. 'It's pretty easy to see who's up to it and who isn't,' Margarete says. 'Actually there's a waiting list.'

As to the food it was always clear what that would be.

'Keeping it vegetarian was partly ideology and partly easiness. New Covent Garden is right on our doorstep and lots of people used to go and pick up all the food that had been left over. It's also difficult to run both a meat and a vegetarian cafe in the same place.'

Certainly it would be in the place the Bonnington occupies. It is a converted Victorian house, much like all the others on this street. The kitchen is more a corridor than a room. The eating space is a deliciously ramshackle affair of bare brick and pink painted walls, sloping floors and wonky tables laid with mis-matching cutlery and crockery. If you want to use the loo you have to venture up the rickety staircase, past the darkened rooms that are used by the Bonnington community centre, a bit as if you are exploring a multiple-occupancy student house. Which is much what it feels like.

On the night I visit the food eats like it was produced by a student, too. I do not actually have a problem with non-meat dishes. I just insist they are good because they have no meat in them, not in spite of the fact.

I love the vegetarian - often vegan - culinary traditions of southern India, for example, or the non-meat dishes of Italy. The introduction of something that once had a pulse will never improve a wild mushroom risotto. What I hate is veggie knock-offs of meat dishes: lousy lasagnes, chillis and roasts.

Tonight, the weekly vegan night, there is a bit of that going on. But mostly what's going on is some criminally poor cooking. The one starter, a soup of carrot, coconut and coriander is grossly under seasoned. A plate of roasted butternut squash with mung beans in a parsley sauce under a crumble is a pile of indeterminate sludgy stodge, the colour and texture of slurry. It is served with smoked paprika potatoes, something which should not suffer from the veganism of the cook; instead they suffer from the incompetence of the cook. They are cold and soggy.

The other main is, if anything, worse, being the culinary atrocity that is vegetarian chilli, served with a pile of cold fried rice and cooling refried beans. At the end comes a chocolate and orange tart, which is one of those dishes which needs dairy products and here doesn't get any. It is a terrible sacrifice of good- quality chocolate. Of course, this is all very cheap, £28 in all for two, including service, but it's still too much for food this poor. The price is held down by the bring-your-own-policy, which we forgot to observe. That was a mistake. A little booze to anaesthetise us against the pain might have helped. The upside is that the vegan responsible for this calamity is only on once a week. There are other cooks doing other things on different nights and I'm sure any of them would be happy to make sure there is a table 'lovingly reserved' for you. Whether there will ever be another table lovingly reserved for me at the Bonnington Cafe is a different matter entirely.

· The Bonnington Cafe, 11 Vauxhall Grove, London SW8. For details of who is cooking when, and how to book, visit www.bonningtoncafe.co.uk