Heat the oil in a pan until hot but not smoking. Drop the basil into the oil and fry for 2 minutes until it turns dark green. Add the onion and garlic and cook for a further 2 - 3 minutes until the onion is soft. Empty the contents of the tomatoes into a bowl and using your hands break them into small chunks. Add the tomatoes, olives and thyme to the pan and bring to the boil. Season with a pinch of sea salt and cracked black pepper. Reduce the heat to simmer and cook uncovered for 40 minutes.
Note: always buy whole tomatoes and break them up with your fingers instead of using a knife. For some reason the metal gives the sauce a metallic acidic taste.
Makes 4 servings (serve = 1 cup)