Step 1

Cook the macaroni following pack instructions, adding the cauliflower for the final 4 mins.

Step 2

Melt the butter in a pan, then stir in the flour and mustard powder and cook for 2 mins. Gradually add the milk, stirring all the time to get a smooth sauce. Add three-quarters of the cheese and some seasoning to the sauce.

Step 3

Drain the macaroni and cauliflower and stir into the cheese sauce. Transfer to an ovenproof dish, then sprinkle over the remaining cheese and flash under a hot grill until golden and bubbling. Serve with a green salad, if you like.