Increase the oven temperature to 450˚F.
Place the roasting rack into the bottom of the roasting pan.
Place the fully wrapped turkey in a large plastic bag, cut the wrapper, lift the turkey out of the wrapper, let any extra liquid drain into the plastic bag, and then place the turkey directly into the roasting pan, breast side up.
Remove the neck and giblets from the neck and main cavity. Place these into the bottom of the roasting pan around the turkey. Discard the wrappings and wash your hands well each time you handle the turkey before touching anything else in your kitchen.
Spoon about 4 cups of the stuffing into the main and neck cavities. The stuffing should be loose and have plenty of space to expand.
Add the remaining stuffing into a baking dish, cover and refrigerate to cook later.
Tie the legs together with kitchen string, tuck the neck flap under the bird and secure with toothpicks if it is stubborn. Fold the wing tips under turkey. It doesn't have to be perfect.
Rub the turkey with melted butter, and season well with poultry seasoning, salt, and pepper.
Scatter the carrots and onion wedges around the bird.
Add 2 cups of water to the bottom of the roasting pan.
Place the thermometer probe into the thickest part of the thigh, and cover the roaster.