Combine cornbread crumbs and breadcrumbs in a large bowl. Pour chicken broth and milk over crumb mixture, stirring well.
Sauté celery and onion in butter until tender; add to crumb mixture, stirring well. Stir remaining ingredients into crumb mixture. Spoon into a lightly greased, shallow 2-quart casserole. Cover; bake at 400° for 15 minutes or until thoroughly heated.