Cut smoked bacon into finely diced pieces. Chop day old bread/brotchen into 1 inch chunks. Wash parsley, shake dry and chop finely. Fry bacon in saucepan until golden brown. Remove from pan and set aside.
Peel onions and dice. Melt butter in pan and saute onions until golden brown and set aside.
Add bread chunks to bacon fat and fry until light brown on all sides. Remove bread from pan, place in mixing bowl and allow to cool. In a separate bowl, stir together milk, eggs and pepper. Pour over bread and mix well. Let stand for at least 3 hours.
Combine the flour, bacon, onion and bread-egg mixture and stir together. Make sure the ingredients are well blended. Dampen hands and form 8 dumplings from mixture. Bring salted water to a boil in a large pot. Carefully place dumplings in boiling water and leave in for 15-20 minutes
Remove dumplings from boiling water and allow water to drain. Arrange dumplings on a platter and sprinkle with bacon.