Classic Tomato Sauce

1 tbs olive oil
1 onion, finely chopped
400 g (14 oz) tin chopped tomatoes
2 tbs tomato puree
1 tsp sugar

Heat the oil in a large pan and fry the onion until soft. Add the remaining ingredients and bring to the boil.

Cover and simmer for 10–15 minutes.

Makes 4 servings.