18- to 20-pound turkey (not self-basting)
Olive oil spray or 1/2 cup olive or canola oil
Salt and pepper
Place a 13×9 metal pan bottom side up on grill. Place a large cookie sheet on top of pan. Turn on both sides of grill on low heat.
Place turkey in roaster pan and rub olive oil all over to coat the whole turkey.
Mix all of your spices and seasonings together in one bowl. Sprinkle over the whole turkey inside and out.
Put the roaster pan on top of the cookie sheet on grill, uncovered and close the lid. Check every hour and add water if needed. Baste with the drippings as desired. Cook until the internal thermometer pops out all the way.