Clean, wash and finely dice the soup greens. Peel and chop the onion. Rinse lentils and bacon.
Heat the oil in a large pot. Sauté the onion in it. Add soup greens, lentils, bacon and bay leaf and pour on approx. 1 1⁄2 l water. Bring everything to the boil, cover and cook for about 25 minutes.
In the meantime, peel, wash and roughly dice the potatoes. Add to the lentils and cook for another 20 minutes.
Pick the bacon out of the soup. Remove rind and dice the bacon finely. Cut the sausages into slices. Heat the diced bacon and sausages in the soup. Season with salt, pepper, vinegar and sugar.