Clean the beans and cut in half once, scald the tomatoes with boiling water and peel them, cut out the stalk, dice the tomatoes, finely dice the onions, press through the garlic, squeeze the lemon.
Put about half of the beans in a saucepan, make a well in the center and add onions, garlic and tomatoes. Layer the rest of the beans on top.
Mix the oil, lemon juice, salt, powdered beaver and sugar well and pour over the vegetables.
Bring the whole thing to a boil and cook covered over medium heat for about half an hour.