1 14- to 16-pound turkey
Kosher or sea salt and freshly ground black pepper
1 large yellow onion (about 12 ounces), coarsely chopped
2 large carrots, peeled and cut into 1-inch lengths
2 large stalks celery, cut into 1-inch lengths
4 large, fresh sage leaves
3 sprigs fresh thyme
1 1/2 cups water
1/2 cup unsalted butter, melted (1 stick)
1. Remove the turkey from the refrigerator 1 hour before you plan to cook it. Remove the turkey from its wrapping. Remove the neck and bag of giblets from the main and neck cavity of the bird. Set aside. Trim off the tail and set aside. Pull off any pockets of fat attached to the skin near the opening of the chest cavity and discard. Pat turkey dry with paper towels. Have ready a large roasting pan with a nonstick roasting rack, preferably V-shaped, set in the pan.
2. Thirty minutes before you plan to roast the turkey, position an oven rack on the lowest level in the oven. Preheat oven to 500 degrees.
3. While the oven is heating, sprinkle the inside of the chest and neck cavities with a little salt and pepper. Put half of the onion, carrots and celery inside the chest cavity. Scatter the rest evenly on the bottom of the roasting pan. Stuff the sage and two of the thyme sprigs inside the cavity. Put the third sprig of thyme in the roasting pan. Add the water to the pan.
4. Tuck the turkey wing tips back and under the wings so they lay close to the chest. Cut a 12-inch piece of kitchen twine and bring the legs together, wrapping the twine around the ends (knobs) of the legs to secure them. Tie a knot and trim any extra length of string. Use a small metal skewer or toothpick to secure the neck skin so it doesn't flop open. Use a pastry brush to brush the turkey with half of the butter. Sprinkle the turkey on all sides with a little salt and pepper.
5. Place the turkey, breast side up, on the rack. Roast for 30 minutes. Lower the oven temperature to 350 degrees. Baste the turkey with the pan juices, and roast an additional 30 minutes. Baste with pan juices. Continue to roast, basting with pan juices after 45 minutes. After another 45 minutes, baste with the remaining butter. Tent the turkey loosely with foil if the breast is browning too much. The turkey is done when an instant-read thermometer registers 165 degrees.
6. When the turkey is done, transfer it to a carving board or serving platter and cover the breast loosely with aluminum foil. Allow the turkey to rest for 15 to 30 minutes before carving to let the juices set. Warm the platter you plan to serve the turkey on.
7. Carve the turkey and serve immediately. Tent the rest of the turkey with foil to keep warm. Remove the rest of the turkey from the carcass later for some fine leftovers.