Kosher Harry, Royal Court Upstairs, London

I started laughing before Kosher Harry began, at the sign which read, "Value. Quality. Civility. Chopped Liver", and looked forward to the comical play it promised. Optimism is not my nature, to put it mildly, but I wouldn't last long in this job if I didn't contravene my nature several times a week. When it comes to unnatural behaviour, however, Kosher Harry leaves me standing. As for humour, it wiped the smile off my face pretty quick.

I started laughing before Kosher Harry began, at the sign which read, "Value. Quality. Civility. Chopped Liver", and looked forward to the comical play it promised. Optimism is not my nature, to put it mildly, but I wouldn't last long in this job if I didn't contravene my nature several times a week. When it comes to unnatural behaviour, however, Kosher Harry leaves me standing. As for humour, it wiped the smile off my face pretty quick.

I have not seen any other plays by Nick Grosso, but I recognise the play's spirit as that of the director, Kathy Burke – or, at any rate, that of Gimme, Gimme, Gimme, which Kosher Harry often recalls, though it is more vulgar and less coherent. A young man who looks as if he'd slept in his suit – in the street – enters the restaurant and is approached by a young waitress, in black fishnet ankle socks, with a hairdo like a pampered Yorkshire terrier's. She tells him at great length about her loathing of a Russian waitress who works there and of another ("Brata-bleedin'-bloody-slava'') who slept with her ex-boyfriend. She swears a great deal, not well, but every couple of minutes calls the man "sir''.

The two are joined by an elderly Jewish woman in a wheelchair pushed by a cab driver whose favourite word is "Blimey''. Though complaining that he isn't being paid, he hangs about, moaning to the man about the old lady, teasing her by saying that Palestinian terrorists are hiding on the premises, and wiggling his fingers over her crotch. The man squeezes her breasts, and the waitress pulls her wig over her forehead and turns her wheelchair to the wall. But talking to the young man so cheers her that she jumps up from her wheelchair to do a Carmen Miranda number. Periodically the sound of a terrible storm is heard, which may represent the growling stomachs of the three would-be diners or the anger of the comic muse.

Is Kosher Harry anti-Semitic? The charge – like that of vilifying the aged or disabled – is too serious for a play that would need to raise its intellectual level to become moronic. One would think the actors could improvise a better piece – indeed, with the flimsiness of its material, and the extent to which the actors repeat it, with increasing violence, Kosher Harry resembles such an exercise more than it does a play. The assignment might have been to switch moods: a long speech, by the taxi driver, about a Pakistani boy is closer to stand-up comedy than theatre, and a speech at the end, by the old lady, introduces a pathetic-realist note to a play that has till then been absurdist-scabrous.

Kosher Harry makes a point of locating its restaurant in St John's Wood, a prosperous Jewish neighbourhood in London. There is only one such establishment there, and I wouldn't like anyone to think there's a connection, for its service and hygiene are far superior and its customers funnier than those shown here. Is Kosher Harry the worst play of 2002? I'd like to think so, but there's only so much optimism I can summon up.

To 11 May (020-7565 5000)