Bring a large pan of lightly salted water to the boil and cook the pasta until almost tender but still slightly firm to the bite. Drain well and set aside.

In the meantime, prepare the cheese sauce. Place the reduced-fat spread, flour, and milk into a medium saucepan and set it over medium heat. Whisk continuously as the mixture warms, ensuring there are no lumps. Once it begins to boil, lower the heat slightly and continue whisking until the sauce thickens and turns smooth and velvety. Stir in most of the grated cheddar cheese, reserving a small amount for topping, and season generously with black pepper.

Add the cooked pasta to the sauce along with the drained tuna, sweetcorn, and chives, if using. Gently fold everything together until the ingredients are evenly coated in the creamy sauce.

Divide the mixture between two small ovenproof dishes. Sprinkle the remaining cheese over the top for a golden finish.

If you plan to freeze the dish, allow it to cool completely before covering and freezing. When ready to eat, defrost overnight in the refrigerator.

To enjoy immediately, preheat the grill and cook until the cheese topping turns golden and slightly crisp. Alternatively, bake in a preheated oven at 170°C (150°C fan) or gas mark 3 for 30 minutes, until the pasta is piping hot and the top is beautifully browned. Serve warm, garnished with extra chives if desired.