MONOGAMY means sharing your life with one person but what if you shared your kitchen with 5.6 million as Britain's favourite TV cook?

Such is the fate of Caroline Mortimer, played by Olivier and Evening Standard award winner Janie Dee, in Torben Betts's new state-of-the-nation comedy, Monogamy, on tour at York Theatre Royal from tomorrow until Saturday.

What happens when the cameras are switched off and the truth comes out in the collision of living a private life in a public eye, asks Betts, writer of such plays as Invincible and The National Joke, the latter premiered at the Stephen Joseph Theatre, Scarborough, in 2016.

"Nigella Lawson's story [leading to her break-up with Charles Saatchi] was kicking off when I started writing this play," says Betts, "But I do stress that this play has nothing to do with Nigella, except that Caroline is a celebrity cook and she's in her 50s."

Instead, he builds his knife-edge drama around the troubled character of Caroline Mortimer, who is married to a retired London banker who did very well out of the recession. "They're very wealthy and very unhappy – once you have a certain wealth, it makes no difference – and they now barely speak to each other in their big Highgate house," says Betts.

"When you take the camera away, Caroline's life is in freefall, and all her chickens come home to roast on one night when there's a huge storm as Mother Nature takes her revenge on silly humanity."

Betts set himself another task: "I wanted to write a play in continuous time, obeying the Aristotelian principle of theatre. That's why it's set on one night, as a two-hour play with one scene, and that's a particularly difficult challenge when you're writing social realism," he says.

As well as adaptations, such as The Seagull – in which Janie Dee also starred, prompting Betts to write the role of Caroline for her – Betts is noted for his works rooted in the aforementioned social realism. "You always want to test yourself as a writer, and Monogamy is broadly in the same area, depicting predominantly middle-class people screwing up their lives when first-world privilege is not enough for them, so it's Ayckbournian rather than Howard Barker-esque," he says.

You may have seen the tour poster with Janie Dee' brandishing a chef's knife. Will it feature, Torben? "You don't show a gun at the beginning of a play without using it by the end, as Chekhov once said." he says.

As it turns out, Betts is not a great watcher of Nigella, Delia et al. "I do find the proliferation of cookery programmes interesting, and though I don't watch them, I'm aware of them, when no-one can afford those poncy meals."

The Original Theatre Company in Monogamy, York Theatre Royal, tomorrow until Saturday, 7.30pm plus 2pm Thursday and 2.30pm Saturday matinees. Box office: 01904 623568 or at yorktheatreroyal.co.uk