There can be few better build-ups to a character’s first entrance than that afforded to Grandma Kurnitz in Neil Simon’s Lost in Yonkers. You know that this German-Jewish New York-resident is going to be a matriarchal force not just to be reckoned with but also the lynchpin of the whole story well before Bernice Stegers sets foot on the stage, and Stegers doesn’t disappoint.

Mrs Kurnitz rules her surviving family – who sons, two daughters and two grand-sons – as well as the convenience store she and her late husband originally set up with the proverbial rod of iron. Her other children died young, and she’s clear-sighted about the fate of her extended family left behind in Poland and Germany. You can’t love her, even like her, but you can understand her and (as the story unfolds) respect her. It’s a superb part and Stegers matches it superbly.

The catalyst for the action is the financial scrape into which Eddie Kurnitz has crumbled. Financing his wife’s medical care has put him into the clutches of a loan-shark. He needs to earn money – fast – and the 1942 boom in scrap metals occasioned by the fall-out from Pearl Harbor is just such an opportunity. So he plans to board his two teenage sons with his mother and stay-at-home sister Bella while he becomes a travelling old-iron salesman.

Bella is not the brightest spark on the block; the threat of institutional care hangs in the air. Laura Howard brings her to life, a damaged soul with an emotional life and physical needs which are only slowly revealed. Director Derek Bond lets the action lurch from comedy to something approaching tragedy with a sure touch; for all the wisecracks and situations contrived to show up everyone on stage, we are never allowed to forget their actual, very human predicaments.

Jos Slovick as younger brother Jay and Keith Ramsay as his slightly older sibling Arty may not be model houseguests for their grandmother, but then neither is their uncle Louie (Nitzan Sharron), a gun-toting bag-carrier for some extremely nasty (not to say downright dangerous) people. After the first scene we don’t see much of the teenagers’ father Eddie, though Jonathan Tafler makes him into a sympathetic person who cares for his sons as he cared for their mother. It’s just that he’s not very good at coping with life.

The set by James Perkins gives us the almost monochrome Kurnitz apartment, adequately furnished but with no sense of real comfort, over the store. It’s backed by a top frieze of brownstone houses, all curtained windows behind which one feels the neighbours lurking, ready to comment and to gossip. At street level, it’s indicated, a certain degree of menace stalks the sidewalks. The cinemas to which Bella is so attracted are part of another world and a quite different sort of reality.