Tommy Tiernan, Soho Theatre

Tommy Tiernan tells us not to take him seriously at the start of his latest show, Out of the Whirlwind. “I’m like a cow mooing for the sake of mooing,” he says – which neatly explains the surreal riffs in a mesmerising 80 minutes, but also lets him off the hook for some of his edgier material. He has often courted controversy in his native Ireland, and there is the occasional line tonight that draws a shocked response from the audience.

Tiernan is in full fire-and-brimstone preacher mode when addressing us loudly without the aid of his microphone, other times whispering intimately as if in a confessional, or getting on bended knee in the more expressive sections of the show, which covers ageing, parenthood, the Catholic church and much else besides. These are big subjects, which lots of comics like to pore over, but ones that Tiernan – part philosopher, part clown, but wholly himself – tackles with a freshness that most others lack. And it's not all high-falutin' – he manages to get in some very good dick jokes while talking about a recent vist to the British Museum.

He talks about how welcome a fading male libido can be in a happy and settled marriage

Tiernan is only 46 but has an old soul, and much of the evening is spent talking about his ageing body. He describes his bushy grey beard poetically as "like a ditch in winter", and talks about how welcome a fading male libido can be in a happy and settled marriage, Tiernan being married for the second time and a father of six. George Clooney hilariously comes in for a kicking in this section of the show, much to the delight of the men in the Soho Theatre, if not necessarily the women.

Tiernan likes to unsettle his audience. He has an interesting if cruel cure for obesity, and thinks that the newly marriage-enabled gay people in Ireland shouldn't just be allowed to adopt children, they should be forced to (“That would knock the craic out of it”). And in a gentle anecdote about playing football with his sons he recounts how his daughter comes along and ruins things with her insistence on it being done her way, leading to what at first appears to be a surprisingly old-fashioned take on the battle of the genders, if such a thing actually exists. But then we discover he’s an equal-opportunities offender; grown women in straight relationships may well be mental but men are arseholes, so honours even.

There’s a delightful devilment to Tiernan’s humour, obvious here in his tour-de-force finale. It’s a story that begins with an encounter with Irish Travellers and at first we laugh guiltily at his retelling of the incident (which may or may not have happened) complete with pitch-perfect accents, only for it to have several turns before the ultimate twist, which completely upends our expectations of where we thought the tale was going. The rather sweet payoff enables us to leave marvelling not only at the expert comedic plotting involved, but also the winning guile of the man who tells it.

• Tommy Tiernan is at the Soho Theatre, London W1 until 20 June