Fry an onion & garlic on medium heat in olive oil
Until semi transparent and a bit brown
Add tin of tomatoes, half the tin of water, tomato purée, a few drops of Worcester sauce and a teaspoon of vegetable stock powder
Turn down, put a lid on and cook for 10 minutes
After 10 minutes...
Put on some pasta
When the pasta is nearly done....
When the pasta is nearly cooked, stir some tuna into the sauce
And some basil leaves if you have them
Top the pasta with the sauce and serve with grated cheese if you have it.