Peel the potatoes, carrots and kohlrabi. Cut the potatoes and kohlrabi into small cubes, cut the carrots into not too thin slices. Rinse the cut vegetables cold in a kitchen sieve. Cut the pointed cabbage into rectangular, bite-sized pieces and wash them too.
Fry the minced beef in hot oil until crispy, seasoning it with salt, pepper and the sweet paprika.
Put the vegetables in a saucepan and bring to the boil with the vegetable stock and a few whole stems of rosemary. Let the vegetables simmer for 7 minutes at medium temperature, then add the pointed cabbage and minced meat and simmer for another 3 minutes until the potatoes are cooked through. Add the milk and remove the saucepan from the stove, covering it.
Squeeze half a lemon and wash and chop the parsley. Season the soup with lemon juice, freshly grated nutmeg, pepper and paprika to taste, and remove the rosemary.
Arrange the soup in bowls and decorate with parsley.