Spiced crab mac 'n' cheese

Melt the butter in a large pan over a low heat and sizzle the whites of the spring onions, the Old Bay seasoning and the paprika until the butter is foamy and aromatic. Stir in the tomato purée and flour until the ingredients form a paste. Cook for another minute or two to toast the flour a little, then turn the heat up to low-medium and add the milk, a little at a time, whisking well until you have a smooth, thick sauce (you may not need all the milk).

Meanwhile, bring a large pan of salted water to the boil and cook the pasta following pack instructions, then drain and set aside.

Stir the cheddar, half of the parmesan, the mustard and crabmeat into the sauce. Check the seasoning – the Old Bay spice mix is salty and spicy, so you may not need to add much salt or pepper. Tip in the cooked pasta and mix well. Pour into a baking dish (ours was 25 x 30cm and 7cm deep). Combine the breadcrumbs, remaining parmesan, the green parts of the spring onions and a pinch of paprika in a bowl, then scatter over the dish. At this stage, the mac ‘n’ cheese can be cooled completely and chilled overnight, or frozen, well covered, for two months. Defrost in the fridge overnight before baking.

To cook, heat the oven to 200C/ 180C fan/gas 6. Bake the mac ’n’ cheese for 25 mins (add another 10 mins if cooking from chilled) until the topping is golden and crunchy and the sauce is bubbling at the edges.