Cod in Parsley Sauce with Boiled Potatoes

Rain against the window. January, or thereabouts. The kind of evening when you want something plain and warm and good, something that doesn't ask you to be clever. This is that dinner.

Cod in parsley sauce is deeply unfashionable. Nobody is putting it on a menu or photographing it for anything. It doesn't pretend to be more than it is: a piece of fish in a white sauce with potatoes on the side. But there's a reason your grandmother made it, and her mother before her, and the reason is that it works. The fish poaches in milk, the milk becomes the sauce, the parsley turns it green and fresh, and the whole thing comes together in less time than it takes to open a bottle of wine. We're only making dinner.

The trick, if there is one, is the poaching milk. You infuse it first with a bay leaf and a few peppercorns and half an onion, then cook the fish in it gently, then use that same milk to build your sauce. Nothing is wasted. The sauce carries the flavour of everything it has touched. This is old cooking, sensible cooking, the kind that makes you wonder why we ever stopped doing it.

I wrote it down in the notebook last winter: cod, parsley, potatoes, Tuesday, rain. That was enough to bring the whole evening back. The kitchen smelled of warm milk and butter. The plates were hot. The fish fell apart under a fork. Right food, right evening.