The raw materials for this one-woman Nigella-the-musical are irresistible: the subject is the verbally-and-otherwise voluptuous celebrity cook Nigella Lawson; the performer Raelene Isbester has excellent cabaret chops; the Broadway-lite songs cover topics from life in the spotlight to tips for keeping your cake moist; and the audience participation is suitably ribald.

But somehow, the recipe doesn’t quite reach its potential, falling into an awkward netherworld between broad parody and homage.

Isbester does a fairly bang-on impersonation, particularly with her physicality (she’s nailed the Nigella head tilt).

She enters the stage in a red-wine-spattered white bathrobe, and proceeds to get stuck into the first of what must be a challenging array of dishes that she scoffs through the show.

Nigella, as we first meet her, is under pressure to come up with a final recipe for her new collection, hinting at off-screen dramas and launching into her first song about the “Pressure Cooker” (accompanied by Shannon Whitelock on piano).

The show picks up pace with some nicely embarrassing audience participation, and a full suite of suggestive puns, both visual and verbal.

But things take a sombre turn, somewhat understandably, when the script turns to Nigella’s well-publicised personal traumas: the early death of her first husband; the shocking scene recorded by paparazzi at a London restaurant when her second husband Charles Saatchi wrapped his hands around her throat; a subsequent court case that dragged her children and personal reputation through the mud.

The broad humour and parody then becomes poignant homage, and a series of tunes try to make some sense of how Nigella might feel (“I will keep my head held high”), with life lessons used as punctuation marks between the various stages of the show.

I sensed the audience didn’t quite know what to make of a show that moved so quickly from masturbation jokes to domestic violence, and neither did I. If you’re not familiar with Nigella’s life and on-screen work, you might become a little lost.

Still, there’s the heart of a potentially great show here. Isbester is a skilled performer who does an enjoyable turn as Nigella. Perhaps it just needs more: more wit, more fun, more pathos, and much more of what is the real Nigella’s greatest hallmark – over-the-top use of language.

Three stars

Nigella – Love Bites is playing at Gluttony’s Spiegel Zelt until March 19.