Before cooking, potatoes must be washed well, using a brush and a special product for washing food. Peel and rinse the potatoes. Place hard cheese in the freezer in advance for 15-20 minutes to make it easier to grate. Wash and dry the dill. To serve, wash and finely chop the green onions.
Prepare the potatoes. Place half the potatoes in a saucepan, add 500 ml of water and cook over medium heat for about 10 minutes after boiling. Then drain the water, add 0.5 tsp. salt and mash the potatoes into a stiff puree. Grate the remaining raw potatoes on a fine grater and place in a sieve. Squeeze the juice out of the potatoes with your hands (do not pour out the juice) and sprinkle with lemon juice to prevent them from browning.
Prepare the filling. Grate the hard cheese on a fine grater. Finely chop the dill and mix with the cheese.
Form zeppelins. In a deep bowl, mix mashed potatoes, raw grated potatoes, potato juice, 0.5 tsp. salt and ground black pepper. Form a flatbread from the resulting mass, place the filling of grated cheese and herbs in the center of it and pinch the edges of the flatbread, forming a large oblong dumpling. Roll each zeppelin in starch.
Weld the zeppelins. Pour 1.5 liters of water into a saucepan, add bay leaf, black peppercorns, 1 tsp. salt and bring to a boil. Carefully lower the formed zeppelins into boiling water and cook for 20 minutes after floating, stirring occasionally to prevent them from sticking to the bottom and walls of the pan.
Prepare the sauce. Cut the bacon into small cubes. Peel the onion, rinse and finely chop. Heat the vegetable oil in a frying pan and fry the onion and bacon for 7-10 minutes, stirring regularly. Then add sour cream, salt, stir, simmer for a couple of minutes, and then remove from heat.
Serve the finished zeppelin dumplings from grated potatoes and mashed potatoes with a sauce of sour cream, onion and bacon. You can put the sauce in a separate bowl, or you can pour it on top of the zeppelins and sprinkle with finely chopped green onions.