The leeks at the market last Saturday were fat and heavy, mud still clinging to the roots. The kind you have to peel back a layer or two to get to the clean, pale heart. I bought four, which was too many for one person, but I knew what I was going to do with them before I'd paid.

This is an autumn casserole, really, or early winter. It needs the weather to have turned. It needs the kind of evening where you close the curtains before six and the kitchen becomes the warmest room in the house. Chicken thighs, because they forgive a bit of time in the oven and reward you with flavour that breast meat simply can't match. Leeks, because when they're braised slowly they go from something sturdy to something almost silky. Mushrooms for earthiness. Cream because it pulls the whole thing together into a sauce you'll want to eat with a spoon.

Wales claims the leek, but every kitchen in Britain has claimed this dish. Fair enough. It belongs wherever someone is standing at the stove on a cold Tuesday, making something quiet and good for the people at the table. We're only making dinner. But dinner, made properly, made with care, is no small thing.

I wrote it down in the notebook last week. Chicken, leeks, cream, thyme. Rain against the window. Enough.