THE 30 Million Minutes of the title equates to the 56 years of Dawn French's life, the clock hand ticking away on Lez Brotherston's typically swish, hi-tech set as another two hours go by.

The show is a frank French confession, rooted in her 2008 memoir Dear Fatty, only this time lived out in the public glare rather than by the bedside lamp. It hides nothing, reveals much, and not for the first time makes you wonder why a performer appears happiest partaking in normally private dinner-table chat in front of more than a thousand strangers.

Given French's comedy status, you might have expected 30 Million Minutes would be a solo stand-up show – it would have been her first – but the involvement of theatre director Michael Grandage, as well as Brotherston, indicates that this is a different stage animal. As much theatre, as comedy, with shards of tragedy too.

There may be the energy of stand-up, but not the audience interaction or the impromptu, improvised moments. Instead, the show is choreographed with slick graphics, film and photographs, everything running to a set pattern in a scripted monologue, performed by French in Brotherston's asymmetrical fashions in black.

French must play off the screen's images and a series of questions, such as How Do You Be A Daughter? and How Do You Be A Wife?, in contrast to her last stage show with Jennifer Saunders six years ago or her television work, where French's comic timing in partnerships is so astute. In the regimented 30 Million Minutes, everything is internalised, navel-gazed and then expressed candidly, as if a psychiatrist's couch has been placed on public display by the director, who wants French to hold nothing back.

This goes against the grain of our natural default position of restraint and concealment, and consequently such honesty and free expression could be awkward on stage, but French's personality pulls it off.

This goes against the grain of our natural default position of restraint and concealment, and consequently such honesty and free expression could be awkward on stage, but French's personality pulls it off.

On the one hand, she gives out plenty of the trademark roly-poly cheeriness; ; the "look-at-me-being-funny" performer since childhood; and the self-deprecating wit, especially in a guided tour of her body parts, calling her down-below "Mumford and Sons, the bearded ones". On the other hand, the Dear Fatty serious side of Dawn has deeper impact.

Among those thoughtful passages are the real reason she lost so much weight (a cancer scare, followed by doctor's advice) and her reflections on the end of her marriage to Lenny Henry. Above all, she is struck in a collision of confused thoughts over the suicide of her father, an RAF officer who had hidden his chronic depression from his children.

This passage is recorded, as French stands still, looking at the photo of her father, rather than at the audience: a moment of privacy among so many onlookers while the questions she can never ask him stack up. She was only 19 at the time, but she celebrates everything he did bring to her, especially confidence and encouragement, and makes a plea for fathers to be the best dad they can be to their daughters.

She lifts the mood again, talking of her late mother, her daughter Billie, her friends, her non-celebrity husband number two. The effect is to cut the umbilical cord of stardom to become one of us. "We're all ***kers; we're all strange; we're all ***king marvellous," she concludes. She has a point.