Chop the onion and garlic, fry in the oil in a large saucepan and sauté until translucent. Wash the beans, cut off the tips, cut into pieces approx. 4 - 5 cm long, add to the onions.
Add canned tomatoes and spices (except vinegar), stir well. Cover and simmer until the beans are quite soft. Then season with balsamic vinegar and thicken with tomato paste.
Tastes very good with pan-fried food (e.g. with lamb steaks) or pure cold with baguette. You don`t want the beans floating in the tomato sauce. Also easy to prepare in a Roman pot.