THE ILLUSTRATED KITCHEN BIBLE
1lb (450g) elbow macaroni
6 tbsp unsalted butter, plus more for the baking dish
1 cup fresh baking crumbs
1/4 cup all-purpose flour
1 tsp dry mustard
pinch of ground nutmeg
1 3/4 cup whole milk, warmed
2 cups shredded sharp Cheddar cheese
4 oz (115g) fresh mozzarella cheese, drained and finely diced
1/2 cup freshly grated Parmesan cheese
Bring a large pot of lightly salted water to a boil over high heat. Add the macaroni and cook for two minutes less than the time indicated on the package instructions. Drain well and set aside.
Meanwhile, preheat the oven to 400°F (200°C) and butter a three-quart (3 litre) ovenproof serving dish. Melt 2 tbsp of the butter in a frying pan, add the bread crumbs, and stir well until coated. Set aside to cool.
Melt remaining butter in a large saucepan over medium heat and whisk in the flour, stirring constantly, for 30 seconds (do not let flour brown). Stir in the mustard and nutmeg, remove the pan from the heat, and slowly whisk in the milk.
Return the pan to the heat and bring the mixture to a simmer, whisking almost constantly. Cook for three minutes.
Remove from the heat. Stir in the Cheddar cheese until it melts. Stir in the macaroni and the mozzarella, transfer to the baking dish, and smooth the surface.
Stir the Parmesan cheese into the reserved bread crumbs and sprinkle over the macaroni and cheese.
Place the dish on a baking sheet and bake for 25 minutes, or until heated through and golden brown on top. Let stand for two minutes. Serve straight from the dish.