Shan Khan should be the epitome of calm. Speaking to me on the phone during his first holiday in three years, he’s staring out across the tranquil waters of Lochgilphead. Yet, the subject of theatre clearly has his hackles raised. Since bursting onto the playwrighting scene in 2001 with his award-winning debut, Office, Khan has been creating fast-paced theatre for modern audiences. And doesn’t mince his words about what spurred him on.

‘One of the reasons I started writing theatre was I was so sick of paying to sit and watch a bunch of self-indulgent shit,’ he proclaims. ‘Theatre should be more instant and entertaining than any other medium, because it’s in your face and you’re sitting two feet from the action.’ Khan’s latest play looks set to hit audiences right between the eyes. The tale of a poor Muslim restaurant worker and wealthy Sikh daughter of a Glasgow curry king, Heer Ranjha is a heady mix of sex, violence, music, dancing and tragedy.

Yet, the tale itself started life as an ancient Punjabi romance, before being translated into an 18th century poem by Waris Shah. ‘I read Shah’s poem while I was doing some research,’ says Khan, ‘thinking it would be about 20 stanzas tops. But man alive that thing went on and on for pages and pages – it was like a novel of a poem.’ In the end, Khan whittled the tale down to the fundamentals – a love story not dissimilar to Romeo and Juliet, although scholars would suggest that Heer Ranjha got there first.

‘This is really the story of a guy who has given up on the world,’ says Khan, ‘and only because of the love of a woman does his faith in life become re-kindled. For me that was the kernel of the story.’ In the original tale, Ranjha falls out with his family, is spurned by his faith and ends up attempting suicide by throwing himself into the Ganges. A boat belonging to Heer passes by and rescues him. In Khan’s version, much the same happens – only with a Glasgow twist.

‘Ranjha throws himself off George V bridge and floats down to Springfield Quay where someone on a pleasure boat yanks him out of the water,’ he explains. ‘The Ganges is obviously important to this story and the Clyde is virtually a sacred river in Glasgow.’

Growing up in Carluke, where his dad ran a video shop, Khan watched three films a day. Now based in London, he writes plays for what he dubs ‘the DVD generation’. So what can audiences expect from Heer Ranjha? ‘Well they’ll definitely get bang for their buck,’ promises Khan. ‘And everything that should be in a film – because what we’re doing is a film on stage, that’s how I like to see it. It’s Romeo and Juliet meets Reservoir Dogs.’

With the lead characters coming from different faiths, the story is ripe to explore religion and the changing face of racism in Britain – not that Khan wants to be seen as didactic. ‘I don’t write issue-based plays,’ he says. ‘But there are definitely issues that have to be addressed. And whether you agree or disagree, it will make you think and get you talking.’

Heer Ranjha, Tramway, Glasgow, Fri 21–Sat 29 Nov (not 23 & 24).