Beat the egg yolks in a bowl. Add the onions, matzo meal, salt, pepper and shortening. Mix well. Preheat the oven to 350 f. Beat the egg whites until stiff but not dry. Fold them into the onion mixture. Pour into a greased 2-quart casserole or baking dish. Bake for 40 minutes.
VARIATIONS: can be made by adding sliced eggplant, green peppers or shredded cabbage between layers of matzos.
