Turn on broiler. Rinse beef and chicken livers thoroughly, and cut away membranes and extra fat. Cut beef liver into 1-inch pieces; chicken livers can remain whole. Place beef and chicken livers in a large baking pan, and drizzle with corn oil (pour oil into a flatware tablespoon and drizzle over livers; 2 tablespoons are ample.) Broil 8 to 10 minutes (keep an eye on it to make sure it doesn't burn.) Turn liver pieces, and broil for another 5 minutes. Liver should be fully cooked and lightly browned on both sides. Chill in refrigerator. In a large skillet, heat 1 tablespoon plus 2 teaspoons corn oil and the same amount of schmaltz, and saute onions, stirring occasionally, until well browned. Chill in refrigerator. In food processor, combine liver, onions, hard-boiled eggs, 2 tablespoons schmaltz, salt and pepper, and blend until smooth. You will have to do it in batches. Chill before serving.
Recipe courtesy of Sharon Lebewohl, author The 2nd Ave Deli Cookbook