To Brine or Not To Brine - If you prefer to brine your turkey, do this the day before you plan to cook it.
Brining helps season and draw moisture into the meat to keep it flavorful and juicy. A good rule of thumb is to use 1 cup of table salt and 1/2 cup sugar for every gallon of water. I allow at least 8-12 hours but no more that 24 hours. Add onions or herbs to the water and put into a container or brining bag so that the turkey is completely submerged. It must be kept cold, either in the refrigerator, or an ice chest with lots of ice around the brining bag or container. When finished discard the brine.
If you don't want to brine the turkey then skip this step.
Remove giblets from inside of turkey and set aside. Thoroughly wash the turkey, removing any feathers or quills and clean out the inside of the cavity. Pat the inside and outside completely dry and set aside to continue air drying.
Peel onions and cut them into wedges or thick rings, do not separate the layers. Clean the carrots and celery and cut into 3-4 inch chunks. Cut the apple into wedges.
In a large roasting pan place most of the onions, carrots, celery, garlic and apple into the bottom of the pan. Add the stock or water and put the roasting rack into the pan.
(Note) If you are not going to use the giblets and neck for anything else, put those pieces into the bottom of the roaster.
Put the dry turkey onto a large platter and liberally spread the butter all over the surface of the turkey, around the wings and legs, and inside the cavity. This works best when the butter is room temperature and soft, but if you prefer to work with melted butter that's fine. It will start to get solid on the cold turkey. Put butter inside the cavity and under the skin of the breast and thighs, being careful not to tear the skin. Secure large flaps of excess skin and fat with toothpicks to close up the neck cavity. Also leave on the big the tail piece. Put any remaining butter into the roasting pan. You need a lot of butter to create the fat for making turkey gravy later.
If you like to inject your turkey, now is the time to do it. I don't.
Liberally sprinkle salt and pepper into the cavity and all over the outside of the turkey. Take the remaining onions, celery, carrot, garlic and apple and put that inside the cavity. If you like the flavor of rosemary, thyme, or sage then add a little fresh pieces to the cavity. These are strong herbs so a little goes a long way.
Set the turkey on the roasting rack BREAST SIDE DOWN. This allows the butter and fat from the skin and cavity work its way into the breast meat to keep it super moist. If you MUST, you can put the breast side up. Tie the legs together with string to hold all of the vegetables on the inside.
Put the oven rack on the lowest position inside your oven and put the turkey into a COLD oven. Close the door and set the temperature to 500 degrees. Once the oven has reached 500 degrees set your timer for 1 hour.
DO NOT OPEN THE OVEN DOOR! After 1 hour of baking turn the oven off and leave the door CLOSED. NO PEEKING! I do this right before going to be and in the morning the whole house will smell like roasted turkey and it will be completely cooked and juicy.
*THIS IS THE TRICK TO A BEAUTIFUL BIRD:
Use heavy duty aluminum foil and double it. Use a piece long enough to tent the turkey over the top leaving an opening on both ends for the air to flow through. I just tuck the foil between the pan and rack to hold it in place and fix it so that the foil isn't actually touching the bird.
This is optional, but in the morning if you want to, carefully drain the liquid from the cavity into the baking pan and turn the turkey over. Put it back in the oven on 500 degrees and cook for about 15 minutes to brown the breast. The turkey will remain somewhat warm in the oven but it can be reheated briefly without getting dried out.
Use the fat and drippings in the pan to make your turkey gravy.