Wash parsley, shake dry, pluck off leaves and chop finely. Mix flour, eggs, 1 teaspoon salt, 1 pinch of freshly grated nutmeg and mineral water and parsley with the dough hooks of the mixer to a thick dough.
Then beat vigorously with a wooden spoon (with hole) until the dough starts to bubble. The dough should flow viscously from the spoon without tearing. Cover and leave to rest for about 1 hour.
Peel the onion and cut into strips. Cut the bacon into sticks and fry them crispy in a pot without fat. Add onion and steam briefly. Add sauerkraut and braise covered over low heat for about 30 minutes, stirring occasionally.
In the meantime, boil up plenty of salted water in a large pot. Scrape or press portions of spaetzle from the dough directly into the boiling water. When the spaetzle rise to the top, lift them out, quench and let them drain.
Heat butter in a large frying pan. Fry the spaetzle for about 10 minutes while turning. Stir the sour cream into the sauerkraut. Season to taste with salt, pepper, 1 pinch of sugar and possibly caraway. Fold the sauerkraut into the spaetzle and serve.