Our oven quit working the night before Thanksgiving so I had to improvise and decided to cook our 28 lb. turkey on the grill. I placed a metal 13x9 pan bottom side up on the grill then a large cookie sheet on top of that. I put the turkey, uncovered (in a turkey roaster pan) on top of that so the bottom would not char. It cooked in half the time it would have taken in the oven and what a wonderful idea it turned out to be...my whole family loved it and it was the juiciest and most tender turkey I have ever cooked! We have cooked our turkey this way every time now and it is always perfect!
Place a 13x9 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.