Wash leg slices, cover with 1 1/2 litres of water in a pot, bring to the boil. Clean, peel and wash the soup greens. Cut half into large pieces. Skim stock, add peppercorns and prepared soup greens, simmer at medium heat for about 1 1/2 hours.
Bring milk and butter to the boil, stir in semolina. Bring to the boil, remove from heat. Season with salt, pepper and nutmeg. Let it swell for about 5 minutes. Whisk egg, stir in. Cut remaining soup vegetables into thin strips (julienne).
Remove leg slices from the stock. Pour broth through a sieve. Bring to the boil again, reduce heat, add vegetables. Cut out dumplings from the semolina mixture with 2 damp teaspoons, cook everything in the hot stock for about 10 minutes.
Remove meat from the bone and cut into cubes. Heat briefly in the hot broth. Wash the chives, dab dry, cut into small rolls, stir into the soup just before serving. Arrange in plates.