Drain the herring and cut into bite-sized pieces. Chop the pickles, onions and apples and put everything in a bowl.
Mix the sour cream with the sour cream in an extra container and dilute with a little milk. Season with pepper and pour over the salad ingredients. Add allspice grains and bay leaf and let everything steep. It is best to prepare the evening before, because the fish has to be cooked well.