Mix the whole egg into a foamy mixture. Add the oat flakes and the grated Parmesan and stir to a mixture. Season the mixture with herb salt, pepper, onion powder (if you like, you can of course also use diced onions), grated nutmeg and a little parsley and mix again with a spoon. Let rest in the refrigerator for about half an hour.
Peel, wash and cut the parsnips into thick strips. Bring the parsnips to a boil in salted water. Shape the dumpling dough into about three medium-sized dumplings and place them in the boiling salted water with a spoon. Cook for approx. 10 minutes at medium temperature with the pot closed (attention: do not let it boil over!).
Then take the dumplings out of the water with a spoon, pour off the remaining water and serve the dumplings with the parsnips.