Bring a large pot of water to the boil. Add the stock cube and 1/2 teaspoon of salt and stir to dissolve
Add the pasta and set a timer to cook it for 2 minutes less than it says on the packet. Drain the pasta into a large bowl but keep 80ml of the cooking water to one side
Mix the cream cheese with half of the passata until smooth
Add the cream cheese mix, remaining passata and tinned tomatoes to the pasta bowl and mix well
Add the sweetcorn, a large handful of grated cheese, drained tuna, chopped basil, salt, sweetener (optional) and chilli flakes and stir to combine
Transfer to an ovenproof dish and drizzle with the reserved pasta water and sprinkle the remaining cheese on top
Bake for 20-30 minutes or until the cheese has melted. Garnish with more chopped basil and serve