Wash and clean the beans and cut into bite-sized pieces. Steam with a little salted water in a closed pot for about 15 minutes. If you like, you can add a few sprigs of savory. Drain and collect 2 tablespoons of cooking water. Rinse the beans in cold water and let them cool in a colander.
Peel and finely chop the onion. Mix with the bean water, salt, pepper, vinegar and oil. Pour the dressing over the cooled beans. Crumble the sheep`s cheese and mix it with the lettuce with the roughly torn basil leaves. Let everything stand for about 1 hour.