Peel and grate 1.5 kg of raw potatoes. Squeeze out very well (the potato mixture must be very dry) and place in a bowl. Season with salt and brew with boiling water (1/4 l).
Now grate or crush 500 g of boiled potatoes. Add to the raw potatoes and mix everything together well.
Meanwhile, toast the white bread cubes in a pan in melted margarine.
Divide the dumpling dough into 12 equal pieces. With wet hands, gradually press it wide and place the white bread cubes in the middle. Now shape the dumplings and pour them into 2 liters of sparkling salt water. Let it simmer for about 15 minutes and let it steep for another 10 minutes.
Important: Use a wide pot without a lid to cook the dumplings so that the dumplings do not stick to each other. Make sure that the cooking water boils again quickly after inserting the dumplings so that the dumplings do not disintegrate.
The mass is designed for 4 people, but it is also enough for 5 or 6 people (depends on your hunger).