Cut the bread into 1/2 cm cubes. Remove the bacon rind and cut the bacon into 2-3 mm cubes. Peel the onion and dice very finely.
Gently fry the bacon in a frying pan until the fat has run out. Add the butter, stir in the onion and fry until golden. Mix the contents of the pan with the bread, parsley and 1 tbsp chives.
Whisk together the egg and milk and season with pepper, but only a little salt as the bacon is already salty. Pour the egg and milk mixture onto the bread and bacon. Dust with flour and knead together well by hand. Leave to rest for 30 minutes. Then knead the dumpling mixture again briefly and using moistened hands form 12 small dumplings. Place in a large pan of boiling, salted water and cook gently over a low heat for 10-15 minutes.
Meanwhile heat the beef broth. Lift the bacon dumplings out of the water with a slotted spoon or skimmer, drain briefly then put 3 dumplings into each of 4 soup plates with the beef broth. Serve sprinkled with the rest of the chives.