1 small onion, diced
1 tbsp oil
1-2 cloves garlic
quite a lot of thyme
1 tin plum tomatoes
Fry the onion until soft but not browned. Add the garlic and thyme. Add the tin of tomatoes and cook until soft and smooth (about 20 minutes)
The sauce can be blended smooth or left chunky. If the tomatoes are poor quality, thin or sharp, then a bit of sugar can be added.
Cheat with a good quality tomato sauce – Seeds of the Earth are quite good despite being organic.