This is an important evening for me,” pleads Hans Teeuwen, the Dutch comedian who has abandoned star status at home for a stab at success in Britain. “Please find me funny.”

Well, you couldn't say the first-night crowd of his sold-out run quite ruptured themselves laughing. Parts of his contrary capering played to silence; others to joyful roars. Many of them from me. Because at his best, Teeuwen (pronounced Tay-when) is about as funny as funny gets. Orthodoxies? He hates 'em, not least those of a comedy show. So his big opener is an attack of crippling mock-nerves - “It's going to be hilarity at the top of our priority list,” he stutters, amid dry heaves - before contorting his roguish face to unnerve his audience. Because Teeuwen is not, joking aside, a comedian who needs our say-so. He goes off on long flights of fancy, talking about imaginary films, or about the underwater spaceship he chances upon on holiday in France.

Comic invention has often been compared to jazz improvisation - Teeuwen makes the comparison palpable, launching into his stupid analysis of his alien captors' decor with all the passion of John Coltrane both paying tribute to and trashing My Favorite Things. His debate about which he prefers, colour or black-and-white films - a pathetic issue rendered rainbow-coloured by the range and depth of his responses - is the funniest thing I'll see all year.

So his bum notes sound doubly bum amid such peaks. Nonsense it may be, but his attitude to women is squirm-inducing. Maybe that's the idea, but his simulated sex session feels adolescent, whether or not it's a comment on the tae kwondo-practising nutter who may or may not be delivering it.

Teeuwen's excellent English isn't always subtle enough to sell his personas distinctly. Is he speaking deliberately Groucho-like, or is that just a Dutchman speaking snappy, Americanised English? Are these characters or Hans Teeuwen?

No doubt he's happy with the ambiguity - apple carts are a spur to mischief for Teeuwen, not a place to find apples. Playing at his grand piano, he's Duke Ellington, Les Dawson and Animal from the Muppets. Singing a closing number about Nostradamus while bashing out rythms on an inverted amphora, he sets up patterns for just long enough to make undermining them matter. Even his curtain call is a brilliant mockery.

Don't try this at home - Teeuwen gets away with it, sexism aside, by being a pig-headed satirist and a phenomenal performer. I'm not sure he'll find mainstream success - he's too comfortable with discomfort. But the acting, the absurdism, the comic commitment? That translates just fine.

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