pat the turkey dry. remove the giblet and neck, and set aside for making gravy or stock (if desired). place the turkey on a rack in a roasting pan.
mix together the dry brine, including the salt, brown sugar, and pepper.
rub the dry brine all over the turkey skin (breast & back) and inside the cavity. Let the turkey sit uncovered overnight in the fridge.
remove the dry brined turkey from the fridge and rinse off the brine (don't forget to rinse the cavity, too). pat turkey and roasting pan dry.
stir together the garlic sage butter ingredients. rub the garlic sage butter all over the turkey breast, wings & back.
stuff the cavity of the turkey with the 'cavity' ingredients. pre-heat oven to 450ºF. place turkey in the pre-heated oven, then reduce the temperature to 325°F.
roast for 2 hours, basting with pan juices every 45 minutes, before taking the temperature.
When turkey is cooked through, remove from oven and allow to rest for 30 minutes.