In A Skillet, Cook Beef And Onion Over Medium Heat Until Meat Is No Longer Pink; Drain. Stir In Soups. Transfer To A Greased 8-In. Square Baking Dish. Cover And Bake At 350 Degrees F For 25-30 Minutes Or Until Heated Through. Uncover; Sprinkle With Chow Mein Noodles. Bake 5 Minutes Longer Or Until Noodles Are Crisp.