Wash the bacon and lentils. Put the bacon and lentils in a pot and bring to the boil with 1 1/2 litres of water. Clean, wash and finely dice the soup greens. Peel, coarsely dice and wash the potatoes.
Add everything to the lentils and cook for 30-45 minutes (depending on how soft you want the lentils to be). Remove the bacon. Remove the rind and dice the bacon finely. Cut the sausages into slices.
Add bacon cubes and sausages to the soup. Add vinegar and sugar. Season to taste with salt and pepper. Arrange soup in bowls and serve garnished with parsley if desired.