Roasted Beetroot Soup with Horseradish Cream

January. The garden is bare and the light goes early and there's a particular kind of cold that settles into the kitchen by four o'clock. This is a soup for that kind of evening. It asks for very little, a bag of beetroot, an onion, some stock, an hour, and it gives back a bowl of something so deeply coloured it stops you for a moment when you ladle it out.

Roasting is what makes this. Raw beetroot tastes of earth and not much else. Boiled beetroot tastes of the water it sat in. But beetroot roasted in foil until it's soft and concentrated and almost sticky, that tastes like something worth sitting down for. The sweetness deepens in the oven, and the colour holds. When you blend it with stock, the whole pan turns a crimson so vivid it looks theatrical. It isn't. It's just a beetroot being honest about what it is.

The horseradish cream is the thing that turns a good soup into the right soup. A spoonful of soured cream spiked with enough horseradish to make your nose tingle, dropped into the centre of each bowl. White on crimson. The sharpness cuts through the sweetness and neither wins. That's the balance you're after. I wrote it down in the notebook last winter: beetroot, horseradish, Tuesday, rain on the window. Right food, right evening.

There are few better feelings than putting a warm plate in front of someone on a cold night. This bowl does the work for you. The colour says everything before the first spoonful.