Soak the beans in cold water overnight or for 8-12 hours. Rinse, pour into a pot, pour in cool water, bring to a boil. Cook under the lid on low heat for 1 hour.
About 30 minutes before the end of cooking the beans, get the yogurt and tomato paste from the refrigerator, so that they are not cold. Wash and dry the lettuce leaves.
Put the beans in a colander. Allow excess water to drain.
Mix the tomato paste, natural yoghurt and olive oil in a separate bowl.
