1. Turkey: Preheat oven to 425 degrees, with rack on bottom. Mash together butter, grated zests, minced sage and thyme, 1 tablespoon salt, and 1 teaspoon pepper. Pat turkey dry. Loosen skin of breast and thighs; rub herb mixture under skin. Season inside cavity and outside with salt.

2. Fill cavity and neck end lightly with stuffing. Transfer remaining stuffing to a 1-quart baking dish; cover with parchment-lined foil. Tie legs and tuck wing tips under. Transfer to a roasting pan fitted with a rack. Bring wine, orange juice, orange-zest strips, whole sage and thyme sprigs, and 2 1/2 cups water to a boil. Dampen a piece of cheesecloth with wine mixture; drape over turkey. Pour remaining liquid into roasting pan.

3. Roast turkey 30 minutes; baste with pan juices. Reduce temperature to 350 degrees and roast 30 minutes more. Remove cheesecloth; baste. Continue roasting, basting bird and rotating pan every 30 minutes, until a thermometer inserted into thickest part of thigh (avoiding bone) registers 150 degrees to 155 degrees (for a conventional turkey, 165 degrees), about 1 hour, 30 minutes more, adding water to pan as needed to prevent scorching (if bird is browning too quickly, tent with foil). Transfer turkey to a platter; let stand 45 minutes. Reserve pan with drippings for gravy.

4. Meanwhile, bake remaining stuffing 25 minutes. Uncover; bake until heated through and crunchy on top, about 20 minutes more. Carve turkey and serve, topped with more sage and thyme sprigs.

5. Gravy: While turkey is resting, pour pan drippings into a fat separator; let stand until fat rises to surface. (Or use a large glass measuring cup and skim fat from top with a spoon.)

6. Bring 1 1/2 cups stock to a boil in roasting pan over two burners, scraping up browned bits from bottom of pan with a wooden spoon. Whisk together remaining 1 cup stock and flour; stir into pan. Boil until thickened and reduced, about 5 minutes.

7. Stir in defatted pan juices; cook until heated through. Season with salt and pepper. Serve hot, in a gravy boat.