“I can’t laugh, I’m in a concentration camp.” She re- emerged, still holding the broken toilet chain in her hand, to find her father waiting by the souvenir stall. They both laughed so hard they could hardly stop…As it finally came together, Punch Me in the Stomach is a hilarious, 36-character group portrait of Filler’s extended family. It is also something far more unusual and uncomfortable, a comic (or tragi-comic) meditation on what it is like to be the child of a Holocaust survivor, growing up in an environment where school friends assumed the number tattooed on her father’s arm was his phone number. A mother so haunted by death that, even in the middle of a party, she would say things like: “I bought myself a plot at the cemetery when I was 35. Would you like to go over there tomorrow and see what’s available?” Black humour hardly comes any blacker.

But that is precisely what makes it so exhilarating and liberating.Filler also told me about passing the comedian’s ultimate test. Once, while working as a minicab driver, she was sent to pick up Mr Misery himself, the professionally suicidal singer Leonard Cohen – and reduced him to helpless hysteria: “I told him a very funny Jewish joke – and the guy loved it. I thought he was so cool, I’d never get him to laugh, but he was slapping his thighs and banging on the window. Many years later, when we were doing research for the film, I found one of his songs I wanted for the closing song, so I sent him a fax, phoned him up and started off. ‘You probably don’t remember me…’ ‘Remember you?’ he interrupted instantly, ‘I’ve been telling your jokes for the last 10 years!’ ” n’Punch Me in the Stomach’ 7.00pm, Sat, NFT, London, SE1 Booking: 0171- 928 3232.

The hero of Simon Gray’s 1975 play, Otherwise Engaged, has just bought a new recording of Parsifal but is prevented from sitting down and listening to it by a string of unwanted visitors. The same comic pattern – fastidious man, who wants to shut out the world, repeatedly foiled by irksome interruptions and claims on his sympathy – underlies All Things Considered, a new play by 27-year-old Ben Brown. Except that his protagonist has a more drastic end in mind than a solitary wallowing in Wagner. Brown’s remarkably assured, if old-fashioned-seeming comedy, was inspired by the case of an American professor of applied ethics who, believing that a human being has the right to decide how and when his life should end, put his theories into practice by committing suicide.