Skin and bone the whitefish. Put the fish, salt, pepper, and 6 tbsp of water in an electric blender and blend at slow speed for 4 minutes. Add the pork fat and corn starch and blend for 1 more minute. Scrape the paste from the blender and with wet hands shape the mixture into walnut sized balls. Set aside. Heat the stock (another recipe) in a large pan. When it is hot, add the fish balls one at a time, and simmer over fairly low heat for 8 minutes. Add the lettuce, scallions, and seasoning. Simmer for 1 minute, stirring. Taste the soup and add more salt and pepper if necessary.{$7e}(Original recipe for 4)
