This is an excellent basic sauce for use with pasta and pizzas.
2 tbsp olive oil
You can also make this using 2 tins of tomatoes (in this case you won't need the stock).
Heat the olive oil in a pan. Add the onion and fry for 5 minutes.
Add the garlic, tomatoes, stock, tomato puree and bay leaf. Simmer for 20 minutes, stirring occasionally.
Cool slightly and remove the bay leaf, then whizz in a blender or rub through a sieve. Reheat gently in a pan. That's it!