For approximately 1liter of soup you need 1 red onion, 4 garlic cloves, 1 dried chili optional, a few old pieces of parmesan cheese, a combination of your choice of dried herbs as basil, thyme, bay leaf or oregano or all of it, 500ml of passata, a drizzle of balsamic vinegar and a drizzle of olive oil.Heat a pan. Add a drizzle of olive oil. Add 1 chopped red onion. Bake and stir. Add the garlic, the chili and the herbs. Bake and stir. Add the passata. Rinse the can with 500 ml of water or more. Add the cheese and a good drizzle of balsamic vinegar. The cheese and the vinegar intensify the flavor in a magic way. Allow to simmer for approximately 30 mins. Stir now and again. Blend, add some water if necessary. Taste, add pepper and salt. Serve with fresh herbs of your choice.Easy, tasty tomato soup.Buon appetito.