Prepare corn muffin mix according to package directions; pour batter into a lightly greased 8-inch square pan.
Bake at 400° for 25 to 28 minutes or until golden; cool in pan on a wire rack. Crumble cornbread into a large bowl; set aside. Reduce heat to 350°.
Sauté celery and onion in hot oil in a large skillet until tender. Add soup and next 4 ingredients, stirring until blended; bring to a boil. Pour over cornbread, stirring until moistened. Stir in chopped egg, and spoon into a lightly greased 8-inch square baking dish.
Bake at 350° for 40 to 45 minutes or until lightly browned.
NOTE: You can substitute 6 cups crumbled cornbread for prepared corn muffin mix.