Clean the soup greens, peel, wash and coarsely chop if necessary. Wash and halve the onion. Heat oil in a pot. Brown the onion halves in it. Wash the leg slices and add them to the onion with the soup vegetables, bay leaf and peppercorns.
Deglaze with 2 litres of water, bring to the boil and simmer at low heat for about 1 1/2 hours. Bring milk, butter, salt, pepper and nutmeg to the boil. Stir in semolina and simmer until the dough separates from the bottom of the pot like a dumpling.
Stir in the eggs one by one. Bring a large pot of salted water to the boil. Use 2 teaspoons of the mixture to cut out dumplings and let them simmer in the salted water for 10-15 minutes until they rise. Remove the dumplings and put them aside.
Peel, wash and cut the celery into small pieces. Remove the leg slices with a ladle. Pour broth through a sieve, put it back into the pot and bring it to the boil. Add celery and cook for about 15 minutes.
Cook the peas for the last 5 minutes. Remove the meat from the leg slices and cut into small pieces. Add the meat and dumplings to the soup and heat it up. Season to taste with salt and pepper. Wash the herbs.
Finely chop the parsley, cut the chives into fine rolls and add to the soup.