Bring water to a boil and simmer for about 60 minutes. Peel kohlrabi and cut into slices. Peel and dice potatoes. Lift out meat and cut them into cubes. Add kohlrabi and potatoes to the soup and simmer about 20 minutes, until vegetables is firm to the bite. 5 minutes before cooking time is over, add meat and spice with salt, pepper and nutmeg.
Dice bacon and onion and fry until golden brown. Add it to the pot and season to taste. Serve sprinkled with parsely leaves.