Preheat the oven to 400°F (204°C). Put the legs and wings in a large roasting pan, making sure they have enough room so they’re not crowded. Put the pan in the oven and let the parts roast while you prepare the braising liquid.
In a large skillet over medium heat, melt the butter. Add the onions and season them with salt and pepper. Let them cook gently, stirring occasionally, until softened, about 10 minutes. Turn up the heat and let the onions color a little bit. With a wooden spoon, stir in the flour and tomato paste and mix well. Slowly add first the red wine and then 2 cups of the turkey broth. Bring to a simmer, stirring almost constantly as the sauce thickens. Gradually stir in 2 more cups of broth and stir until the sauce thickens once again. Remove from the heat.
Remove the pan of legs and wings from the oven. They should be nicely golden but not too dark. Pour the braising liquid over the turkey parts, cover the pan tightly with foil, and return to the oven. Reduce the heat to 350°F (176°C) and braise the turkey for about 1 1/2 to 2 hours, depending on the size of your bird, until the legs are tender when tested with a fork. Transfer the braised turkey legs and wings to a cutting board and let them cool slightly.
Strain the braising liquid through a fine-mesh sieve into a saucepan, skimming off any fat that rises. This will be your gravy. Taste the sauce for seasonings and texture. If it’s too thin, reduce it a bit over medium heat until it reaches a consistency you like. Set aside. (The braised turkey process can be done hours ahead or the day before and refrigerated.)
When the braised turkey parts are cool enough to handle, remove the leg meat from the bones in large pieces and tear the meat from the wings. Cut the meat into rough slices and put in a baking dish. Cover and hold at cool room temperature.
Meanwhile, remove the breasts from the refrigerator and let them come to room temperature. The breasts will take only about a half hour to roast, so they can be started up to an hour before dinner in a 375°F (190°C) oven. Put them in a shallow roasting pan, skin side up, and into the oven. Check at 30 minutes—you want an internal temperature of 140°F (60°C). (The temperature will continue to rise as they rest.) Let them rest on a platter, loosely covered, for 15 to 30 minutes before carving.