A favorite tailgating recipe from Nancy Osborne, wife of former Nebraska head football coat Tom Osborne.
Place bread cubes in a greased 13x9x2-inch baking dish. Layer chicken, water chestnuts, and green onions over bread. In a skillet, cook mushrooms and sweet pepper in butter until tender. Layer mixture over green onions; sprinkle with cheese.
Whisk together eggs, milk, soup, mustard, and pepper. Pour over layers in dish and press mixture lightly with a spoon. Cover and chill for 4 to 24 hours.
Bake in a 325 degree F oven for 30 minutes. In a small bowl, combine bread crumbs, and 1/4 cup melted butter. Sprinkle over casserole. Bake about 10 minutes more or until a knife inserted near the center comes out clean. Let stand 10 minutes before serving. Makes 10 to 12 servings.