Rinse the thawed turkey, save neck and organs for making stock later if you desire. Pat the turkey dry and place it breast-side up in the roaster pan. If the lid doesn’t close tightly over the turkey, you will need to break the breastbone to ensure a tight fit. Otherwise, do not use this recipe.
Put some pieces of the celery, apple, onion, and butter in the turkey cavity. Do not overstuff. Put all remaining pieces around the sides of the turkey. Rub a light coating of olive oil on the turkey and sprinkle with salt and pepper.
Add a cup of water to the bottom of the roaster pan and cover making sure the lid fits tightly. The turkey should have some clearance so that it is not touching the roaster lid.
Place the bird in a preheated oven and cook at 500 for one hour, then turn off the oven and *do not open* for 5-6 hours.
For The White Wine Gravy:
Make a slurry by thoroughly combining flour and lukewarm water in a small bowl and mix until smooth.
If you're using drippings from your turkey, allow the fat to separate then remove. Then add turkey stock to large saucepan and bring to a simmer.
Gradually whisk in the slurry. Then cook on medium heat until slurry is incorporated and gravy has thickened, about 7-8 minutes. Be sure to stir occasionally.
Slowly whisk in the white wine and cook on medium heat for about 6 more minutes, or until it is the consistency you desire, add salt and pepper to taste and serve warm.