Clean and salt the fish, set them aside for a full hour, and then transfer to a stewpan. Pour on just enough cold bouillon made from root vegetables, onion, and spices to barely cover the fish. Set the pan on top of the stove and boil for 15–20 minutes over a very high flame. Meanwhile, bring to a boil 1 spoon butter with 1 spoon of the very best flour and add 4 spoons of very fresh, thick sour cream, 1 small lump of sugar, and finely chopped dill. Dilute with enough fish bouillon to make a rather thick sauce. Boil thoroughly and pour over the fish arranged on the platter. Garnish with sliced quenelles that have been wrapped in a cloth moistened in butter and boiled like a sausage.