Combine giblets, neck, and water in a large saucepan. Cook 30 minutes. Drain, reserving 3 1/2 cups broth. Discard giblets and neck.
Sauté celery in butter until tender. Combine celery, remaining ingredients, and reserved broth in a large mixing bowl; stir until well blended.
Spoon mixture into a well-greased 9-inch square baking pan. Bake at 350° for 40 to 45 minutes.