Directions

1. Preheat oven to 325 degrees F (165 degrees C).
2. Mix 2 tablespoons salt, and 1 tablespoon pepper, and poultry seasoning in a small bowl. Tuck turkey wings under the bird, and season cavity with about 1 tablespoon of the poultry seasoning mixture. Reserve remaining poultry seasoning mix.
3. Toss the onion, celery, and carrots together in a bowl. Stuff about 1/2 cup of the vegetable mixture, rosemary sprigs, and 1/2 bunch sage into the cavity of the turkey. Tie legs together with kitchen string. Loosen the skin on top of the turkey breast using fingers or a small spatula. Place about 2 tablespoons butter under the skin and spread evenly. Spread the remaining butter (about 2 tablespoons) all over the outside of the skin. Sprinkle the outside of the turkey with the remaining poultry seasoning mix.
4. Spread the remaining onion, celery, and carrots into a large roasting pan. Place the turkey on top of the vegetables. Fill the pan with about 1/2 inch of water. Arrange a sheet of aluminum foil over the breast of the turkey.
5. Roast the turkey in the preheated oven until no longer pink at the bone and the juices run clear, about 3 1/2 hours. An instant-read thermometer inserted into the thickest part of the thigh, near the bone should read 165 degrees F (75 degrees C). Remove the foil during the last hour of cooking. Baste the turkey with the pan juices.
6. While the turkey is roasting, make stock: place neck, heart, and gizzards in a saucepan with the bay leaf and water. Simmer over medium heat for 2 hours. Strain the turkey giblets from the stock, and discard giblets. There should be at least 4 cups of stock.
7. Remove the turkey from the oven, cover with a doubled sheet of aluminum foil, and allow to rest in a warm area for 10 to 15 minutes before slicing. Pour the pan juices, about 3 cups, into a saucepan and set aside. Skim off the turkey fat from the pan juices, reserving about 2 tablespoons.
8. Heat 2 tablespoons of the turkey fat and 1 tablespoon butter in a saucepan over medium heat. Transfer the onion from the roasting pan into the skillet. Cook and stir until the onion is browned, about 5 minutes, then stir in the flour. Continue to cook and stir for about 5 minutes more; whisk in 4 cups of the skimmed turkey stock and the reserved pan juices until smooth; skim off any foam. Stir in the balsamic vinegar. Simmer until the gravy is thickened, whisking constantly, about 10 minutes. Stir in 1 tablespoon of chopped sage, and season to taste with salt and black pepper.