Wash and blanch the kale thoroughly. Drain the cabbage and let it cool down a little, chop finely. Peel and finely chop the onion. Heat lard in a pot. Put onion and kale into the pot and braise for about 3 minutes.
Add stock, bring to the boil and simmer for about 1 hour. Prick the cooked sausages several times with a fork and add them to the kale about 20 minutes before the end of the cooking time. Meanwhile wash the potatoes, bring to the boil covered with water and cook for about 20 minutes. Drain potatoes, rinse with cold water and peel. Heat the oil in a pan. Add potatoes, season with salt and pepper. Fry over medium heat for about 10 minutes while turning. After about 5 minutes sprinkle sugar on top. Take out the cooked sausages.
Add potatoes, season with salt and pepper. Fry over medium heat for about 10 minutes while turning. After about 5 minutes sprinkle sugar on top. Take out the cooked sausages. Season the kale with salt, pepper and mustard. Arrange kale, cooked sausage and potatoes on plates