55g cheddar cheese or similar, grated plus extra for sprinkling on top
Freshly ground pepper
Serves 6 as a side dish
Heat the oven to 200C/395F/Gas 7
Remove the green outer leaves from the cauliflower, cut a deep cross in the bottom of the stem then steam whole over a pan of boiling water for 10 minutes. Remove the cauliflower from the heat and leave to cool. The cauliflower should not be cooked thoroughly, just lightly steamed and beginning to soften.
Place the butter and flour into a large saucepan. Over a low heat stir the butter and flour until the butter has melted and the flour is incorporated. Add the salt and mustard powder (if using) and continue stirring for 2 minutes.This is to cook out the floury taste and to soften the starch grains in the flour ready to make the sauce.
Turn the heat up to medium and add the milk in one go and whisk furiously until all a smooth sauce is formed. Continue stirring until the sauce is thickened and glossy (about 5 minutes) If the sauce is very thick add a little more milk, the sauce should be thick but still a little on the runny side. Add the grated cheese and stir until melted. Remove from the heat.
Break the cauliflower florets from the thick, central stalk taking care not to break it into tiny pieces. Place the florets in a greased baking dish large enough to hold all the florets in one layer.
Pour the thickened cheese sauce over the cauliflower ensuring all the florets are covered. Sprinkle with grated cheese and a good twist of black pepper.
Bake in the hot oven until the sauce is bubbling and golden brown on the top, approx 30 minutes.
Serve your cauliflower cheese as a side dish with your Sunday Lunch, it also makes a great side dish, vegetarian dish and is lovely on a baked potato.