Wash the nettles and boil them in hot water for approx. 3 minutes. Pour them into a sieve and blend to a smooth purée. In the meantime, chop the onion and fry it in a little butter until golden-brown.
Cut the bread into cubes of approx. 0,5 x 0,5 cm. Put it into a bowl, add eggs, milk or cream and onion and let it soak for a few minutes. Season with salt, pepper and nutmeg and combine to a dumpling-"dough". Hold your hands under water and form dumplings with your wet hands. Boil or steam them for 15-20 minutes and serve with melted butter/olive oil, pepper and parmesan cheese.
Freeze the rest of the dumplings on a plate or board and put them in a bag once they're frozen.