Preheat oven to 425°. Spray rack of a roasting pan with cooking spray.
Place turkey, breast side up, on prepared rack, and pat dry with paper towels. Rub turkey inside and out with 2 tablespoons oil; sprinkle with salt and pepper. Place 2 clementine halves and onion wedges in turkey cavity. Tie legs with butcher’s twine. Pour broth into pan. Add rosemary, sage, and remaining clementine halves to pan.
Cut ¼ inch off top end of garlic head, keeping cloves intact. Place garlic, cut side up, on a sheet of foil. Drizzle with remaining 1 tablespoon oil, and wrap in foil. Place foil packet on rack with turkey. Loosely cover turkey with foil.
Bake for 30 minutes. Reduce oven temperature to 325°. Uncover and bake garlic until soft, about 20 minutes more. Remove garlic; continue baking turkey until a meat thermometer inserted in thigh registers 170°, about 1 hour and 55 minutes more. Remove from oven, and let turkey stand for 20 minutes before carving. Scrape any browned bits from roasting pan; reserve 1 cup turkey drippings and roasted garlic for Garlic-Rosemary Gravy. Garnish with rosemary, sage, additional roasted garlic, and Browned Clementine Halves, if desired. Serve with Garlic-Rosemary Gravy.
Recipe by Southern Lady Magazine at https://southernladymagazine.com/roasted-turkey-with-garlic-rosemary-gravy-recipe/