Sort the kale, wash thoroughly several times and drain. Collapse briefly in plenty of boiling salted water. Then drain well and chop roughly. Peel onions and cut them into fine slices. Wash the smoked pork loin.
Heat the lard in a pot. Brown the onions and kale in it. Deglaze with broth and braise covered for about 1 hour. After 20 minutes add the smoked pork. Season to taste with salt, pepper and sugar. In the meantime peel and wash the potatoes. Cook in boiling salted water for about 20 minutes. Cut the Kasseler into slices. Arrange kale, sliced pork and potatoes on plates.
Season to taste with salt, pepper and sugar. In the meantime peel and wash the potatoes. Cook in boiling salted water for about 20 minutes. Cut the Kasseler into slices. Arrange kale, sliced pork and potatoes on plates. Serve with mustard