Creamy, cheesy leek and Brussels sprout gratin

An easy, tasty side dish of winter vegetables.



2 leeks, sliced
200g Brussels sprouts, trimmed and halved if large
25g unsalted butter
25g plain flour
250ml semi-skimmed milk
Good grating of fresh nutmeg
Tsp Dijon mustard – optional
100g mixed grated Gruyère and Cheddar or any strong melting cheese
40g fresh breadcrumbs
Salt and pepper


  1. Preheat the oven to 200°C/fan180°C/400f/gas 6.
  2. Blanch the leeks and sprouts in boiling water for about 3 minutes. Drain and refresh under cold water to stop them cooking, then drain again making sure you drain thoroughly otherwise you may end up with a watery sauce.
  3. Melt the butter in a saucepan over a low heat, then stir in the flour and cook for a couple of minutes. Gradually add the milk, stirring constantly, to form a smooth sauce. Season well with nutmeg, salt and pepper and mustard if using, then add 2/3rd of the cheese.
  4. Stir through the leeks and sprouts, then transfer to an ovenproof dish, mix the remaining cheese with the breadcrumbs and sprinkle on top.
  5. Cook the gratin in the oven for 15-20 minutes and the gratin is golden and bubbling.