Crush the garlic cloves with the back of a knife, so they split, but remain whole. Warm some more oil in a frying pan and add the garlic. Once fragrant and lightly golden, remove from the pan, add the tomatoes (or passata) and cook until they collapse into a sauce. You can pass the tomatoes through a food mill back into the pan or, if you’re happy with the texture, simply tear in most of the basil, add the sugar if you think the sauce is too sharp, and a good pinch of salt.