My daughter loves this and it's simple to make

Grated cheese (as much as you like)
2 Tin's chopped Tomato's
I Tin Tomato Soup
3 Small Tins of Tuna
Pasta (any kind, we use twists or shells)
Salt, pepper and abit of mixed herbs/basil

Boil the pasta till it's cooked
In a large oven proof dish add the Tuna, Soup, Tomato's salt and pepper/ herbs to taste.
Add Pasta and stir well in.
Top with Cheese
Whack it in the oven for 20-30 mins on gas mark 150-200