Place giblets and neck in a large saucepan; add water, bouillon cubes, poultry seasoning, salt, and pepper. Bring to a boil; cover, reduce heat, and simmer 45 minutes or until giblets and neck are tender. Let cool. Cover and chill at least 8 hours.
Discard layer of fat on top of mixture. Pick meat from neck; set aside for gravy. Chop giblets; set aside for dressing. Add canned chicken broth, if necessary, to make chilled broth measure 4 cups. Set aside.
Saute garlic, celery, and onion in butter in a Dutch oven until tender; add 2 cups reserved broth (keep remaining 2 cups broth), giblets, bread cubes, mashed potatoes, cornmeal, dried parsley, cream of tartar, pepper, salt, nutmeg, and eggs; stir to blend. Bake at 325 degrees in a lightly greased 9-inch square pan for 45 minutes. Yield: 9 servings.
