Elmina's Kitchen, National Theatre, Cottesloe, London

New generation, same old recipe

Kwame Kwei-Armah's play, set in present-day Hackney, deals with the problem faced by black people there and elsewhere of how to keep their sons from being seduced by the thrills and money offered by the world of crime. Despite its topicality, though, the situation is one we have seen in many other plays and in movies, in which Jews on the Lower East Side, Irishmen in Depression-era Chicago, or Pakistanis on a Northern housing estate are similarly tempted and bring their families heartache and ruin. Elmina's Kitchen is full of pungent dialogue and humour that cuts as deep as pain, but its many good qualities battle against its familiarity.

Elmina never appears, but her picture - that of a righteous-looking middle-aged woman - looms over the characters who work in or patronise the restaurant named in the title. It is run by her son, Deli, whose other job is trying to keep his own son, Ashley, out of trouble. At 19, Ashley, who has given up his studies and works as his father's delivery boy, is already a father himself but has less interest in his child or its mother than in cars and clothes. Deli's father, Clifton, who left Elmina many years ago, has just returned from Trinidad, and loses no time in adding to the host of local bad examples. The earnest Deli and his new cook, Anastasia, are good, hardworking people, just the sort Ashley despises. He would rather have the approval of Digger, a small-time hoodlum who cannot answer one of his several mobile phones without stretching and preening himself like a panther with an audience. Ashley won't even speak the same language as his father, preferring Digger's warrior-pidgin: "Dat's how me like dem."

Angus Jackson's production is wonderfully cast, but the biggest favour anyone could have done this play would have been to cut it by about fifteen minutes. Its rather stagey, plodding quality could also have been leavened by more poetic moments, such as the ghostly funeral procession that slinks across the restaurant. Much of the talk is repetitious, the plot predictable - it's hardly a surprise when two offstage characters turn out to be dead, for they have never been brought to life. Giving the attractive, commanding actor Paterson Joseph the role of Deli is rather extravagant casting against type. But it's casting - Joseph must suppress his masculinity and physical force - that prevents the character from being bloodless; Deli rejects the advances of his cook, the delightful Doña Croll, because, he says, he has nothing to offer her. Such masochistic drudgery is no advertisement for virtue. Nor is Ashley any more than a collage of headlines about feckless youth.

Where Kwei-Armah excels is in dialogue, especially when he is writing for the two older men, Clifton and his friend Baygee, the irresistibly charming Oscar James. "Dem was de days," Baygee recalls of West Indians' early days in London, "when dey used to feel your bottom to see if you had a tail". He reproves Ashley's insolence with "Don't test me, young man. I lash a man last week, an' he's still fallin' down."

Though he never, unlike several others in the play, flashes a weapon, the true villain of the piece is Clifton, a slick, swaggering cock of the walk who, as incarnated by George Harris, is repellently fascinating. "You look good, and I look great," Clifton says to a woman young enough to be his daughter, touching her with a skilful imitation of tenderness, and giving a snake-hipped promise of pleasure. Clifton's vanity and selfishness have ripped apart his family as effectively as drugs and guns - though constantly urging his son to make good (so that he will look good), Clifton just as constantly belittles him.

Clifton's comment on learning that Deli wants to sell fast but authentic food - "Fast and West Indian is a contradiction" - gets a big laugh, but his elevation of laziness to heritage cultural status poses a problem the play exemplifies rather than addresses. If black men make anti-social characteristics emblems of masculinity, how can we convince our youths to drop these and still feel they are men? How can Deli win over his son if he cannot even move us?

To 25 August (020-7452 3000)