Optional: Lemon slices and fresh herbs for topping
Thaw turkey (plan on about 4 days in the refrigerator or 8-10 hours in cold water).
Remove neck and giblets from body and neck cavities, discard. Place turkey breast side down in a roasting pan. Cross the legs and tie with baking twine if they aren't already tied. Pat the turkey dry with paper towels. Then sprinkle with a thin layer of salt. Let rest 30-60 minutes before preparing to bake.
Pat the turkey with paper towels to dry the turkey. Salt and pepper the inside of the cavity and then fill with onions, lemons and herbs. Create a pocket using the dowel of a spoon on the top and then rub the butter under the skin. Then rub the remaining butter all over the top of the turkey.
Preheat oven to 325°F. Adjust rack if needed.
Roast for 2 1/2 hours (about 13-15 minutes per pound), or until the internal temperature reaches 160°F. Remove from the oven and tent with foil. The temperature will reach 165°F while resting.
Let rest for 15-20 minutes before carving. Reserve any drippings to make turkey gravy. Slice the turkey and serve.
Want to take it up a notch? Rub about 1/4 cup garlic herb butter in between the meat and the skin before baking. https://www.iheartnaptime.net/garlic-herb-butter/