Kosher salt and freshly ground black pepper, to taste
2 tablespoons unsalted butter, softened
3 cups chicken or turkey broth
3 tablespoons flour
Heat oven to 400°. Season the inside of the turkey with 2 tablespoons poultry seasoning, salt, and pepper. Rub butter over the breast and place the turkey breast side down in a large roasting pan. Roast 30 minutes, shaking the pan after about 20 minutes to make sure that the turkey is not sticking to the pan.
Turn turkey over using tongs and an oven mitt; ladle off about one-quarter of the pan drippings and reserve. Reduce oven to 350° and continue roasting until turkey registers an internal thigh temperature of 180°, about 1-3/4 hours longer.
In a separate saucepan, simmer the giblets and neck in chicken or turkey broth, seasoned with the remaining 1 tablespoon poultry seasoning until tender, about 30 minutes. Strain from the broth, then chop cooked giblets into small pieces and remove as much meat as possible from the neck; combine flour with the reserved pan drippings and return everything to the broth. Whisk to combine and simmer until lightly thickened.
Once the turkey is done, transfer to a carving board, tent with a large piece of aluminum foil, and let it rest about 10 minutes. Meanwhile, skim the fat from the remaining pan drippings, reserving 1 cup for the Curried Rice Stuffing, if desired. Place the roasting pan over high heat; add the gravy to the drippings in the pan and scrape up all of the brown bits from the bottom of the pan into the mixture; adjust the seasoning. Carve the turkey and serve with gravy.