Polish Style Herring (Sledz po Polsku)

Soak 4 fine salt herrings in cold water for 24 hours, changing the water several times while soaking. Remove skin, milt, cut off the tail and head, divide into fillets and remove the bones. Arrange the fillets in layers in a glass jar. Between the layers place very thin slices of 2 onions, 10 grains of pepper, 6 grains of allspice, one bay leaf broken into parts, 5 slices of lemon without rind or pits. Combine ½ pint sour cream with the juice of 3 large lemons. Do not salt the sauce. Pour over fillets in the jar (shake the jar to cover fillets evenly. Place covered jar in cool place. Ready to eat in 24 hours. Baked potatoes are served with herring.