Preheat the oven to 375 degrees convection or 400 degrees regular bake.
Grab your big roasting pan and place the wings and necks in it, then spread the vegetables - carrots, garlic, onions - all around. Brush the olive oil all over - doesn't have to be precise or cover everything. Then sprinkle the salt and pepper all around. Spread the fresh herbs on the top. Roast for about 30 minutes. The turkey should be browned and you should hear some sizzling coming from the bottom of the pan.
Place your largest stock pot on the stove top and put all the roasted turkey and vegetables in it. Don't wash the roasting pan yet! Place it stovetop as well over medium to medium high heat and pour in the brandy or your liquid of choice to deglaze the pan. To deglaze is to mix around the liquid while gently prying the pieces of meat or veggies that have been left behind on the bottom of the pan. The liquid should get hot very quickly and the yummies should release easily from the pan bottom. As soon as they are released, turn the heat off and pour this liquid carefully into the stock pot. If you deglaze too long the liquid will quickly evaporate.
Add 12 - 16 cups of water to the stock pot - basically you want to completely cover the turkey and veggies. Add the peppercorns and parsley and more thyme and sage if you'd like.
Bring this to a boil, then partially cover and turn the heat down to maintain a simmer (you should see some movement in the liquid and an occasional bubble but it shouldn't be a rolling boil). Let it cook for an hour and a half or even up to 2 or 3 hours.
Take it off the heat and let it cool off a bit. Then take the large pieces of meat and veggies out and strain them (I like to get every drop but you could just put the large pieces on a plate and nosh on the overcooked carrots and dark meat on the necks and not bother with straining them). Then line your biggest strainer with cheesecloth if you have it, pour the broth through into a large bowl or another pot. Let the strained broth cool for a bit - maybe a half hour and then put it into your storage container of choice and refrigerate or freeze. Any fat will congeal and you can remove it when you use it.