Cook celery and onion in water over low heat until tender; drain. Combine cooked vegetables, cornbread crumbs, breadcrumbs, butter, sage, salt, and pepper in a large bowl; mix well. Add eggs and broth, stirring until well blended.
Spoon dressing into a lightly greased 13- x 9- x 2-inch baking dish. Bake at 400° for 30 minutes or until lightly browned. Cut dressing into squares, and serve with Giblet Gravy.