This recipe comes to us from Ellen Switkes.
3 large onions
3 teaspoons salt (or more)
¼ cup potato starch
lots of pepper
Place fish skin/bones/head in a large pot with water to cover, add 2 carrots sliced thin and one onion sliced thin. Boil. Process all ingredients in food processor. Form fish balls either small or large as you like, drop into boiling stock and simmer for 2 hours. Remove fish balls to bowl, reduce stock, strain over fish and refrigerate. I like it when the stock gels a bit. Serve cold with horseradish.