Cook 280 g of Pasta shapes in a pan of boiling salted water until just under al dente, about 1–2 minutes less than the packet instructions. It will finish cooking in the oven.
Melt 1 tablespoon of Butter in a large frying pan. Add 2 Portobello mushrooms (chopped) and 1 Leek (sliced) and cook over a low-medium heat for 6–8 minutes, until softened and most of the excess moisture has evaporated.
Add 60 g of Spinach and cook for about 2 minutes, until wilted.
Add 240 g of Cooked turkey, 75 g of Light mature cheddar, 50 g of Parmesan, 200 ml of Crème fraîche and 1 teaspoon of Dijon mustard. Season with ¼ teaspoon of Fine sea salt and ½ teaspoon of Ground black pepper.
Stir everything together over a gentle heat for about 2 minutes, until the cheese has melted and the sauce is creamy. Avoid letting it boil rapidly.
Drain the pasta, reserving a little of the cooking water. Add the pasta to the pan with a splash of pasta water and mix well until everything is coated in the sauce. Add a little more water if needed to loosen it.
Transfer the mixture to a large ovenproof baking dish and spread it out evenly.
Sprinkle over 75 g of Light mature cheddar and bake for approximately 20 minutes, until golden, bubbling and piping hot throughout. Finish with 1 g of Fresh basil (chopped) before serving.
Notes
Undercook the pasta slightly. It continues cooking in the oven, so taking it off the heat 1–2 minutes early helps prevent a mushy pasta bake.
Save some pasta water. A little starchy cooking water loosens the sauce and helps it coat the pasta. Add it gradually so the sauce doesn't become too thin.
Cook off excess moisture. Mushrooms and leeks release water as they cook. Let most of this evaporate before adding the crème fraîche to avoid a watery sauce.
Keep the sauce on a gentle heat. Crème fraîche can separate if boiled too vigorously, particularly reduced-fat versions.
For a crispier topping, sprinkle some breadcrumbs over the cheese or place the finished bake under the grill for 1–2 minutes. Keep a close eye on it so it doesn't burn.
Add some freshness with halved cherry tomatoes scattered over the top before baking.
Like a little spice? Add some red chilli flakes to the sauce.
Make it vegetarian by swapping the turkey for cooked leftovers from your favourite meat-free roast, provided they are suitable for reheating. Use a vegetarian Parmesan too.