Dice the onion very finely and sweat it in the oil. Add diced tomatoes or canned tomatoes. Simmer gently for 5 minutes. Squeeze the garlic and add. Now add the other ingredients and simmer gently for half an hour, stirring occasionally until a thick sauce is formed.
Serve warm or cold with meat or fish, ideally from the grill.
Goes particularly well with my fillet skewers with zucchini.