I always roast the bones overnight, well, maybe not roast, but I put them in the roaster, with water and add a spice ball that has pickling spice in it. I add carrot, celery, onion. I add a bit of dill pickle brine. I do add peppercorns. I set the oven at 275 and let it go overnight. The stock is dark brown and has so much flavour. I strain it and then set the stock in the fridge to get any fat to harden. Sometimes I add a bit of fresh ginger and lemongrass, but it depends on how I plan on using the stock. When I make the soup, this is a two-day process given the overnight cooking of the carcass, the chilling of the stock, I add the reserved meat about 10 minutes before the soup is done. It took me a long time to master turkey soup that had a lot of turkey flavour. Treating the carcass this way is what did it for me. My Dad loves my turkey soup. It is all to taste and what I have on hand. But the secret is the stock.