I’ve become disillusioned with Hollywood comedies of late. Perhaps it’s general film fatigue talking, but honestly there’s only so many times you can be subjected to a poorly-scripted collection of half-assed improv twisted into a generic plot before the laughs start to dry up. Which makes a film like The Big Sick – authentic, heartfelt, funny, original, romantic and with an actual goddamn screenplay – feel like a miracle of sorts, a breath of fresh air in a stale theatre stocked with tired also-rans.

Oh, did I mention it stars Kumail Nanjiani? Until now best known for being the best thing about otherwise mediocre comedies (Mike and Dave Need Wedding Dates, Sex Tape, Central Intelligence …and probably Silicon Valley, which I stopped watching after season one), this represents his well-deserved breakthrough into a leading role. Of course, he kinda has to be in the lead, given the film is a loosely-autobiographical story of Nanjiani’s meet-cute-turned-tragic with his now-wife Emily (played in the film by Zoe Kazan). If you don’t already know Kumail, it’s a great introduction; if you are familiar with him, you’ve probably already gone out and bought tickets.

That’s not a decision you’ll regret. The Big Sick is the kind of gentle rom-com you don’t really get anymore. The setting, the jokes, the characters – they’re all rendered with a naturalistic deftness rarely seen since Katherine Heigl and Gerard Butler ground the genre into oblivion. It’s contemporary, too; at 39, Nanjiani is perhaps a touch too old to believably play a struggling stand up still relying on an air mattress in his dinky apartment, but casually populating the screenplay with modern technology avoids the feeling of falseness you might expect.

The film is charming and frequently funny without stepping on its dramatic qualities. Initially, most of the tension centres of Kumail’s Pakistani family – who expect him to agree to an arranged marriage and become a lawyer while he’s at it – but when Emily is admitted to hospital with an unexplained illness, the film takes a sharp turn towards darkness. Watching one’s (ex-)girlfriend fall into a prolonged coma may not sound like comedy gold, but Kumail’s tentative friendship with Emily’s parents (Ray Romano and Holly Hunter) inject some lightness into the proceedings without entirely dissolving the aforementioned dark cloud.

I only have two complaints, really. The first is that the autobiographical context saps the film of any significant dramatic tension; while you don’t really expect Emily to succumb to her illness (this is a comedy, after all), knowing that it’s based on the real story of a happily married husband and wife negates some of the intended anxiousness. That’s a minor quibble, but more substantial is the lack of believable chemistry between Nanjiana and Kazan – you buy them as a casual couple, as great friends (with benefits, perhaps), but you never quite buy the fairytale ending The Big Sick is working towards.

Perhaps that’s for the best. The film doesn’t end with that surge of ‘happily ever after’ you sense that it wants to, but the sense of excited uncertainty it does provide suits its true-to-life aesthetic. After years of comedies with artificially-enhanced drama and contorted attempts at narrative resolution, it’s just immensely refreshing to watch a comedy that feels like real life.