Unstirred: "Cocktail"

The director Homi Adajania's first collaboration with bestubbled, Duchovnyesque hunk Saif Ali Khan was 2005's Being Cyrus, an odd, scratchy black comedy that felt in places as though American Beauty was being pushed, altogether reluctantly, into Hitchcock territory; the film didn't get anywhere worthwhile, finally, but it was interesting as a break from the Bollywood norm. By contrast, Adajania and Khan's latest film, the London-set relationship dramedy Cocktail, is as brash, splashy and pseudo-hip as the Hindi mainstream presently gets. If you're playing Bollywood bingo, you can tick off the following: an establishing shot of the Gherkin; a male lead who works in software development; musical numbers set in nightclubs that look like no nightclub you or I have ever set foot in, and which cue the kind of songs David Guetta might manufacture, if David Guetta were a 35-year-old Asian man, and not a 58-year-old Frenchman; and native walk-on performers who deliver their lines as though they've never spoken English before.

The set-up is an unlikely flatshare scenario, beginning as sitcom, ending two hours and forty minutes later in soap. Veronica (Deepika Padukone), a partygoer whose comedy signifier is her persistent refusal to wear panties, discovers Meera (Diana Penty), a naive young thing lured to the capital by a hoax offer of marriage, sobbing in a bathroom, and invites her to stay at her place. Physically, the two could be twins, which is a problem for the film, as Penty and Padukone - previously one of the most singular creatures in all cinema - swiftly become interchangeable in everything up to and including their initials. Anyhow, their life together is all makeover montages and trips to Borough Market, until one night Veronica picks up Gautam (Khan), a seasoned tailchaser who comes to discover his latest conquest's flatmate is the fresh-off-the-plane beauty he'd earlier put the moves on at the airport. Given the two girls' resemblance, perhaps it's no surprise allegiances should shift - and the lingering kiss Gautam and Meera share while holidaying in Cape Town just before the interval leads us to expect the second half is going to be agonisingly heartfelt. Which it is.

For the most part, the stars are the only thing keeping Cocktail watchable. (It would be easy, if not especially pleasant, to imagine an American version with Ashton Kutcher, Olivia Wilde and Leighton Meester.) Khan does have charisma and comic timing - he shares some sparky moments with schlubby older brother Boman Irani - though they're laid on thick here, as if to compensate for the thinness of the premise. In so far as the film allows her to distinguish herself - and it really does take two or three glances per scene to ascertain whether it's Veronica or Meera Gautam is wooing - Penty makes an appealing debut, downplaying wherever possible, and letting her co-stars handle the zanier, sudsier stuff; and Adajania knows that, if all else fails, he can always cut to Padukone lounging around in a bikini or stepping into or out of a cocktail dress, a tactic that proves more effective than any of the script's attempts to sell us on Veronica's mid-film decision to put on an apron (and, we presume, underwear) and reinvent herself as a devoted housewife.

The problems are familiar ones, centred on Bollywood's continual inability to depict contemporary reality in any even mildly convincing fashion. I don't doubt there are Desi boys and girls at large in the City of London who work in photography or the software industry, and have disposable income enough to holiday in Cape Town and take in waifs and strays. My suspicion, however, is that this audience - which is, after all, the audience Cocktail looks to be aiming at - is getting up to far more with their weekends than smoking, taking discreet sips of Carlsberg, and wondering which of their flatmates to bat their eyelashes at. As a portrait of the London scene, Cocktail holds up only about as well as Hollyoaks' depiction of nightlife in Chester: the result is a film that desperately wants to be a Veronica or Gautam - sexy, worldly, hedonistic - but which actually, when it comes to it, proves rather closer in personality to Meera, being meek, gauche and deeply, deeply conservative.

Cocktail is on nationwide release.