US playwright Jen Silverman’s two-hander – a little bit The Odd Couple, a little bit Thelma & Louise – takes place entirely in an Iowa kitchen.

Sharon (a dazzlingly good Lucy Bell) is a 50-something divorcee living a wholesomely regular life that doesn’t extend beyond a trip to the grocery store on a Thursday and attending a weekly reading group. She seems to spend most of her time fretting about her son, a fashion designer living in New York who never picks up the phone.

Lucy Bell and Belinda Bromilow in The Roommate. Photo © Brett Boardman

Enter Robin (Belinda Bromilow), also 50-something and herself a New Yorker. Edgy and a former potter and slam poet, she is moving into Sharon’s spare room. Chalk and cheese? Well yes – but uncomfortably so: Robin is vegan.

How Robin came to be here isn’t really explained. The “why Iowa?” question is dismissed with the equivalent of a “why not?”

But she’s is clearly on the run from something, and Sharon is squirming with excited curiosity. Bit by bit, over coffee with almond milk (not Sharon’s thing) and then a shared joint (Sharon’s first), Robin guides her guileless roomie towards life choices she would previously have run a mile from. Or called the cops on.

Lucy Bell and Belinda Bromilow in The Roommate. Photo © Brett Boardman

Compared to her better-known The Moors, Silverman’s script is a lightweight confection (100 minutes, no interval), reliant on some broad sketching of city-country/liberal-conservative archetypes.

As such, it’s an open invitation to play for laughs, but here director Lee Lewis takes us in close and her actors play for real. Bromilow’s angular, wary Robin is convincing; Bell’s gushy, goofy spontaneity is delightful.

The Roommate plays at The Ensemble Theatre, Kirribilli until 25 July.