Kosa bel bechamel

Step 1: Heat the oven to 400°F (350°F fan) and lightly oil a 20 × 30 cm baking dish.

Step 2: Warm 2 tbsp sunflower oil in a wide frying pan over a medium heat and cook 1 onion, stirring now and then, until soft and pale gold.

Step 3: Add 2 ¼ lb courgettes, 1 tsp salt and ½ tsp ground black pepper and turn up the heat to medium-high. Cook, stirring often, until the slices are tender and the liquid they release has evaporated. Don't skip this: watery courgettes are the most common reason the bake turns soupy.

Step 4: For the béchamel, melt 2 ⅛ oz butter in a saucepan over a medium heat, stir in 2 ⅛ oz plain flour and cook for 2 minutes until it smells nutty but has not browned.

Step 5: Pour in 3 ¼ cups whole milk a little at a time, whisking constantly, then simmer gently until thick enough to coat a spoon heavily. Season with ¼ tsp ground nutmeg and ¾ tsp salt.

Step 6: Stir about a quarter of the béchamel into the courgettes and spread them in the dish. Pour the rest of the sauce over the top and smooth it to the edges.

Step 7: Scatter over 3 ½ oz mozzarella and 1 ⅜ oz hard grating cheese and bake until bubbling at the sides and golden brown in patches on top.

Step 8: Rest the dish for 10 minutes so the sauce sets, then cut into squares.