Soak herrings in cold water 6 hours. Drain, and dry the fish well. Cut into bite-size pieces.
Weigh the fish. Match their weight with a combination of potatoes, beets, apples and pickles, divided roughly into 4 equal portions. Boil potatoes and beets until done (reserving beet liquid). Peel and core apples. Cut into small cubes, along with vegetables and pickles. Place in a large salad bowl. Add herring bits.
Mix the first 2 tablespoons of vinegar and 2 tablespoons of olive oil, the claret and ½ the juice the beets were cooked in. (If you like sweet-sour salad dressings, put a little sugar in this liquid to taste.) Pour over salad and chill 12 hours.
Just before serving, mix the last 2 tablspoons of vinegar and 2 tablespoons of olive oil in the top of a double boiler over hot water and cook until somewhat thickened. Add salt and pepper to taste. Cool and pour over the salad. Garnish with hard-boiled eggs and parsley.