When he announced his intentions to film a suicide-bomber comedy, Chris Morris made his feature- film debut even more of a hot potato than potential investors might have expected.

Surprisingly, though, Four Lions is quite a traditional comedy. It features likeable characters who might have sprung from a quaint Seventies sitcom, the only difference being that these guys make nail bombs, hate Israel and lament the rise of Gordon Ramsay. Set in the North of England, and played by a largely British-Asian cast, Four Lions tells the story of Omar (Riz Ahmed), a security guard in a shopping mall who dreams of Mujahidin glory. Aided by a white Muslim, Barry (Nigel Lindsay), Omar recruits a sleeper cell, then goes to Pakistan to visit a training camp, where he hopes to be chosen for a mission by one of al-Qaeda's emirs. Unfortunately for him, the project goes horribly wrong, and, unwilling to lose face, he returns to the UK claiming that the mission has been approved.

Here the film becomes the stuff of tabloid headlines. Using the format of an Ealing comedy, with tinges of Seventies farce, Morris delves into the shadowy world of terrorism with extraordinary fearlessness, making these incompetent would-be killers appear daft and strangely endearing. Ahmed, in particular, gives a nuanced and sophisticated performance: his character sees his heroism in the banal terms of The Lion King, and rails against the West while living in a nice suburban home, complete with an Ikea kitchen and fittings.

Given that every bomb in this movie eventually explodes, the grotesqueness of such bad taste is in the eye of the beholder. Here in Sundance, where the reality of suicide bombings isn't quite as palpable as it is in the UK, the crowds lapped it up.

Film-maker's comment: "I sort of feel in a weird way that this is a good-hearted film. It's not a hate film."

Why it will be a hit: Morris is at his jaw-dropping best, creating a warm, likeable comedy about a Muslim terror cell that professes to hate the liberal, Mini Babybel-eating West.