Break down your turkey or get your butcher to break it down for you - I left the drumsticks and thighs intact, so wound up with two thigh/drumsticks, two breast pieces and two wings. He also gave me the carcass to take home for stock.
Preheat the oven to 350?F. In a large skillet, heat a generous drizzle of oil with a generous dab of butter and saute the onion and celery for 4-5 minutes, until soft. Add the garlic and cook for another minute.
Meanwhile, tear or cube your bread into a large bowl. Add the sauteed veggies along with the sage, season with salt and pepper and toss to coat. Melt about 1/2 cup butter and drizzle it over the bread, toss again and spread out in a large, shallow roasting pan. Sprinkle over some chicken stock - enough to moisten the bread without making it soggy. (This kinda depends on the type and age of your bread - just go with your gut.)
Place the chicken carcass and wings in an ovenproof skillet, drizzle with a bit of oil if you like, and slide it into the oven. Pat the leg and breast pieces dry with paper towel and rub all over with oil or soft butter. Set on top of the stuffing mixture and sprinkle with salt and pepper. Pull the leaves off a few sprigs of thyme and sprinkle that over too. If you like, tuck a few sprigs into the stuffing as well.
Roast for 1-1 1/2 hours, or until a thermometer inserted into the thickest part of a breast or thigh reads 160?F (it will continue to rise in temperature as it rests). Rest for at least 15 minutes before slicing and serving. While it rests, make the gravy; move the bones to a pot for stock, and make the gravy on the stovetop out of the browned bits in the bottom of the pan.
Serves 8 or more.