Cut the smoked pork loin into cubes (approx. 2 x 2 cm). Peel and roughly dice the onions. Clean or peel and wash the soup vegetables and cut them into pieces.
Heat the oil in a frying pan, add the diced pork, fry for about 5 minutes, turning. Add the onions and soup vegetables and fry for 2-3 minutes. Deglaze with balsamic vinegar, apple juice and 800 ml water. Stir in stock and bring to the boil, cover and simmer for about 15 minutes. Add the lentils and let everything else boil for about 25 minutes.
In the meantime clean and wash the spring onions and cut them into fine rings. Wash the marjoram, shake dry, pluck the leaves from the stalks and chop coarsely. Season lentil stew with salt, pepper and 1 pinch of sugar. Arrange in deep plates and sprinkle with spring onions and marjoram.