Boil up about 1 l water and broth. Peel, wash and chop the potatoes. Add frozen soup vegetables to the stock and cook covered for about 15 minutes.
For the Gremolata, wash the lemon hot, grate dry and finely grate the rind. Wash parsley, shake dry and chop finely. Remove 4 tablespoons of stock. Mix parsley, lemon peel, broth and oil, season with salt and pepper.
Press sausage meat directly from the skin as dumplings into the hot soup. Season soup with salt and pepper. Serve with Gremolata.