Heat the grill to high and bring a large pan of salted water to the boil. Grill the bacon slices for 5 mins or until crispy, then drain on kitchen paper and cut into small pieces.

Cook the pasta following pack instructions. Add the cauliflower to the pasta pan for the final 8 mins, so that it is just tender, then drain, reserving a small amount of cooking water.

Melt the butter in a small pan over a low heat, then stir in the flour and cook for a couple of mins. Gradually stir in the milk, mixing well between each addition. Bring to a simmer, then cook for a few mins until thickened. Season, add the mustard and half the grated cheese. Stir until the cheese has melted and the sauce is smooth.

Tip the pasta and cauliflower back into the pan along with the reserved cooking water. Stir through the cheese sauce and bacon, then transfer the mix to a baking dish. Mix together the breadcrumbs and remaining cheese, then sprinkle over the pasta. Cook for 5 mins under the grill until browned. Serve with a salad, if you like.