Sauce: 40 g butter
40 g flour
1 tbsp capers
1 egg yolk
1 tbsp sour cream
salt
white pepper
Soak the herring fillets in mineral water for 3 to 4 hours. Later drain, chop or grind in a hand mixer.
Knead onion, squeezed out bread, minced meat and egg well together. Season with salt and freshly ground pepper. Mix in the herring puree well. Form meat dumplings with wet hands or two tablespoons (8 to 10 pieces) and cook in boiling water. For the sauce, heat the butter in a saucepan, stir in the flour, add 1/2 liter of the hot clear soup and cook for 5 minutes. Mix in the drained capers. Stir some sauce with egg yolk and sour cream and add to the sauce form. Season to taste with salt and freshly ground pepper. Form the drained meat dumplings into the sauce and serve with boiled potatoes.