1 whole turkey, neck and giblets reserved, about 10 to 12 pounds
1 recipe classic sage and sauges stuffing or your favorite stuffing recipe (see note)
12 tablespoons (1 1/2 sticks) butter, divided
1 tablespoon finely minced fresh thyme leaves (or 2 teaspoons dried thyme)
1 tablespoon finely minced fresh sage leaves
1 tablespoon finely minced fresh rosemary leaves
2 medium garlic, minced or grated on microplane (about 2 teaspoons)
Kosher salt and freshly ground black pepper
1 tablespoon vegetable oil
1 large onion, roughly chopped
1 large carrot, peeled and roughly chopped
3 stalks celery, roughly chopped
1 1/2 quarts low-sodium chicken stock or turkey stock
2 bay leaves
1 teaspoon soy sauce
1/4 teaspoon marmite
1/4 cup flour