Preheat oven to 374 degrees. Brush bottom and sides ofcrust, evenly, with egg yolk;bake on baking sheet untillight brown, about 5 minutes. Remove crust fromoven. Combine sliced apples, lemon juice, half cup sugar, quarter cup brown sugar, 3 tablespoon. flour, salt, cinnamon andnutmeg. Mix well and spoon into crust. Mix remainingflour, sugar, brown sugar and butter with fork or pastryblender until crumbly. Sprinkle topping mixture, evenly,over apples. Bake on baking sheet, about 50 minutes. Coolon wire rack. Serve at room temperature.