John Kearns, Soho Theatre

John Kearns introduces himself as himself as he comes on stage then, very carefully - tenderly almost - he lays out a blonde wig, a pair of women's high-heeled shoes and a skimpy dress on the floor. They stay there until the final segment of his show, untouched and without mention. He puts on a ridiculous oversize tonsure wig and a pair of joke-shop false teeth.

Oh and he is wearing a horse costume, and “rides” Trigger as he performs the first bit of the show - which he tells us is about "disguise, expectations and failures".

Kearns won the Edinburgh Comedy Awards best newcomer gong for this, Sight Gags for Perverts (how one critic described Stanley Kubrick's Dr Strangelove when it was released in 1964). Kearns, who until recently was a guide at the Houses of Parliament but has long been a keen student of comedy, packed that away for later use; it has, of course, nothing to do with the show's content, which is an accomplished piece of absurdist theatre.

Absurdist theatre, therefore, means heavy on the performance and light on the jokes, although Kearns has a beautiful turn of phrase and there's an occasional laugh-out-loud gag. Describing Trigger's dilapidated state – a blow-up horse that's rather deflated - he says, “It's a puncture... I shot him,” which is not only clever but was delivered beat-perfect.

One has to immerse oneself in Kearns's resolutely daft world to get full value

The show is loosely bound together by a story about a trip Kearns took to Berlin; along the way there are unexplained and seemingly unconnected elements in which he sings along to Bruce Springsteen songs, plays a recording of advice about comedy from Woody Allen (a vauntingly brave thing for a debutant comic to do), the unexpected pleasures of poo and the difficulties of miming a hotel shower on stage.

Kearns is a gentle soul and his bizarre shtick, much of it self-deprecating and almost child-like, is mostly endearing. What a shame, then, that dragging a young man in the front row to come on stage and dance provocatively, bum wiggling, in front of his mates, looked horribly like bullying on the night I saw the show. The guy was clearly humiliated and the wrong target.

I must confess I found a lot of Sight Gags For Perverts edging towards tedium and I suspect one has to immerse oneself in Kearns's resolutely daft world to get full value. But then, in the final few minutes, by which time he's in women's clothing, the points he wants to make - about identity and masculinity – suddenly pierce through and you realise Kearns is a humorist of great subtlety, and an original talent of whom we'll hear a lot more.

• John Kearns at Soho Theatre until 31 January