Cut bread rolls into 1 cm (approximately 1/2 inch) cubes, place into a bowl.
Cook bacon in a hot pan for a few minutes, add onion and saute until translucent. Add parsley and bread cubes, mix well.
Whisk eggs with milk and pour over bread mixure. Add flour and butter, mix well and season with salt and pepper, let stand for 30 minutes.
Bring salted water to a boil in a large pot, reduce heat and simmer gently.
Place one dumpling into water for test. If it falls apart, add more flour to the mixture.
With moistened hands, shape mixture into dumplings and cook in simmering salted water for about 15-20 minutes. Remove with a slotted spoon and drain. Arrange on plates and serve.