Proper Mac & Cheese

Method

1. Heat the oven to 200°C / 400°F fan. Boil the macaroni 2 minutes short of the packet time — it finishes cooking in the oven.
2. Melt the butter in a saucepan, stir in the flour, and cook this roux for 2 minutes until it smells biscuity rather than raw.
3. Add the milk a third at a time, whisking hard until smooth before the next addition. Simmer 5 minutes until it thickly coats a spoon.
4. Off the heat, stir in the grated cheddar, the mustard, nutmeg and plenty of salt and pepper. Adding cheese to a boiling sauce makes it grainy.
5. Fold in the drained pasta, tip into a baking dish, and top with the parmesan mixed into the breadcrumbs.
6. Bake 20 minutes until bubbling at the edges and deep golden on top. Rest 5 minutes before serving.