In skillet, over medium-high heat, cook bacon until crisp. Remove and crumble bacon; pour off all but 3 tablespoons drippings. Blend flour into reserved drippings. Gradually add reserved broth; cook over medium heat, stirring constantly, until thickened. Stir in cheese until melted. In greased 2 quart baking dish, layer 1/3 each potato-onion mixture, sauce and bacon. Repeat layers twice. Bake at 400 degrees for 35 minutes. Makes 6 servings.