This is observational comedy at its most painful. The agonisingly repetitious exchange between a surprisingly patient Cathy and her aged in-laws about what constitutes a buffet will strike a chord with many.
It's a slightly frustrating perspective because Cathy, having the patience of a saint, is nicer and perhaps more passive than at least some of the rest of us. But stick with it, because Mum will certainly grow.
It's actually a surprisingly gentle tale -- full of humanity and filled with subtle and, yes, some not so subtle comedy. But, all of it delivered in a wonderfully understated way in an ordinary, suburban setting.