Beat egg whites until foamy and gradually add the sugar, beating until stiff. Spread into a 9x13-inch baking pan. Bake in a slow oven (275-degrees) for 1 hour. Turn off oven and let meringue stay in oven overnight. Spread lemon filling on top of meringue. Make vanilla pudding, using only 1 cup milk. Let stand while you whip the cream. Fold the cream into pudding. Spread on top of lemon layer. Sprinkle with chopped nuts and refrigerate.