Cut the White Bread Roll into small cubes and place them in a large bowl.
Warm the Whole Milk (do not boil) and pour it over the bread cubes, pressing gently so all pieces absorb the milk; let sit until softened.
Finely chop the Onion and sauté it in Butter over medium heat until translucent and slightly golden, then let it cool a little.
In a separate bowl beat the Eggs and stir in the cooled sautéed onion, chopped Parsley, a pinch of Fine Salt, a grating of Ground Nutmeg and some freshly ground Black Pepper.
Pour the egg and seasoning mixture over the soaked bread and mix gently to combine; if the mixture is too wet to shape, fold in some Breadcrumbs until it holds together but remains soft and springy.
With wet hands, form the mixture into golf-ball–sized dumplings and place them on a lightly floured tray to rest for a few minutes so they firm up.
Bring a large pot of salted Water to a gentle simmer (not a rolling boil). Carefully lower the dumplings into the simmering water, reduce heat so the water barely moves, and cook them until they rise and are firm throughout, about 15–20 minutes.
Remove the Semmelknödel with a slotted spoon, drain briefly, and serve hot alongside your favorite roast, gravy, or saucy mushroom dish.
