Cut the rolls into slices and pour the hot milk over them. The milk must be completely absorbed, but the rolls must also be completely soggy, possibly take even more milk.
Sauté the onion cubes in butter. Add these with the eggs and the starch to the rolls. Knead everything well and season. Cut the hard cheese into small cubes and knead in.
Make a test dumpling and add it to boiling salted water. Then just let it simmer. If the test dumpling does not hold, add a little more starch or flour. Then shape the dumplings and cook as you would with the test dumpling.
Clean and wash the spinach. Finely dice the onion and sauté in the butter. Add the spinach and cook while stirring several times. Season with salt, pepper and nutmeg. Then add the cream and let it boil through. Taste and serve.