Roasted Beetroot with Horseradish Cream and Walnuts

October, and the beetroot at the Saturday market looked like something pulled from the earth five minutes ago. Soil still clinging to the skins, leaves still attached, that deep crimson you only get when they've had their time in the ground and nobody rushed them. I bought more than I needed, which is the only way to buy beetroot.

Roasting does something to a beet that boiling never will. The heat concentrates the sugars until the edges caramelise and the centre turns dense and sweet, almost fudgy. The kitchen smells of damp earth and something faintly mineral, a smell that sits right on the border between savoury and sweet. You'll know they're done before you open the oven. Your nose will tell you.

Horseradish is the counterweight. Without it, roasted beetroot is all warmth and sweetness with nowhere to go. The horseradish cream cuts through with a sharpness that clears the sinuses and wakes the whole plate up. Walnuts bring a bitter crunch, watercress brings pepper. Four ingredients, each one doing a different job, none of them competing. This is the kind of salad you put in the middle of the table and let people help themselves from, spooning the cream alongside, reaching for more bread.

I wrote it down in the notebook last autumn: beetroot, horseradish, walnuts, watercress. Friday. Cold outside. Sometimes a list of ingredients is all the recipe you need.