Instructions

1. At least 24 hours before (or up to two days before) serving, remove the turkey from its wrappings, take out the giblet and innards, and pat dry with paper towels. Rub all over with the kosher salt, slipping it under the skin where possible and salting the inner cavities.
2. Place the turkey in a large pan or foil tray, then loosely cover with tin foil and refrigerate. A few hours before cooking, uncover and remove the turkey from the fridge so that it comes to room temperature.
3. Preheat the oven to 325F. Make a “vegetable trivet” in your roasting pan: arrange half of the onions, half of the apples, the celery, carrots and potatoes in an even layer in the bottom of the pan.
4. Make your sage butter: Tear 15-20 sage leaves from the bunch and chop finely. Combine the chopped sage with the butter, shallots and black pepper.
5. Transfer the turkey to a large cutting board. Rub the sage butter all over the outside of the turkey, then slide your hand under the turkey skin and rub the butter on the breast, leg and thigh meat. Stuff the inner cavity with the rest of the onions and apples, then tie the legs together with kitchen twine.
6. Place the turkey breast-side down (backbone facing up) in the roasting pan. Roast for 1 hour, then carefully flip the turkey so that the breast side faces up. Turn the oven up to 400F, then roast for an additional 75-80 minutes.* Check for doneness by inserting a meat thermometer into the thickest part of the thigh — it should read 165F. (The juices should also run clear.)
7. Remove the turkey from the oven and transfer it to a cutting board. Tent the bird with tin foil and let it rest for at least 30 minutes. Transfer the drippings to a measuring cup and use them to make gravy (if desired). Carve the turkey and serve.