You cannot fault Francesca Martinez for confidence. She may have to be accompanied onstage due to her cerebral palsy, but once she settles into her chair this self-styled "wobbly comedian" - best known for being mistaken for a drunk in the Kate Winslet episode of Extras - soon hits her stride, delivering a thoughtful hour of sit-down comedy.

The material in In Deep is not always cutting edge but Martinez's engaging character lets her get away with murder when delivering a threadbare gag about George Bush or David Beckham's intellectual shortcomings. Everyone from Richard Dawkins to Eddie Izzard is currently doing better anti-bible riffs, but not with such a wide smile.

Sometimes she is ahead of the game. This show, which premiered in Edinburgh last summer, imagined Nike maths classes (swooshes for correct answers instead of ticks) long before McDonald's announced their A-levels.

If there were more moments like this and her corking portrait of Jesus on The Apprentice ("You've had your last supper, you're fired"), Martinez would be great rather than good. Luckily for her - and us - that armour-plated personality protects the weaker material.

• From Wednesday to 23 February (020 8985 2424, www.hackneyempire.co.uk).