Here's a great way to roast a large turkey (18 pounds or more).
Cook Time 5hours
Resting Time 1hour
1large turkey, over 18 pounds
1carrot, cut in chunks
1 stalk celery, cut in chunks
1 onion, cut in chunks
salt and pepper to taste
Preheat the oven to 250 F.
Remove the innards and neck from the turkey cavity. Rub the turkey all over with butter. Sprinkle salt and pepper all over. Put the carrot, celery and onion chunks into the stomach cavity. Truss the bird (or pin it) to keep the wings close to the body.
Put a rack in a large roasting pan and put the turkey on it, breast side down. Add a cup of water to the bottom of the pan.
Roast at 250 for 3 hours, basting now and then.
Turn the bird over so it's breast side up, baste and then roast another hour.
Leave the bird breast side up. Turn the oven up to 400. Roast another hour. The USDA recommends the internal temperature of 165 °F as measured with a food thermometer in the innermost part of the thigh and wing and the thickest part of the breast.
Take the turkey from the oven, leaving it in the rack on the roast pan. Cover loosely with foil and let it rest at least half an hour. I always let it rest while I bake all the side dishes.
Large Roast Turkey from Pam Anderson https://cheapcooking.com/roasting-a-big-turkey/ November 28, 2008