1 whole turkey breast, boned, halved, and butterflied by your butcher, 5 to 6 pounds total
Kosher salt and freshly ground black pepper
3 tablespoons extra-virgin olive oil, plus 1/4 cup
1/2 pound pancetta, cut into 1/2-inch pieces
1 1/2 pounds ground pork shoulder
10 prunes, pitted and quartered
12 chestnuts, roasted, peeled, and halved
2 cups fresh bread crumbs
1 cup freshly grated Parmigiano Reggiano
2 eggs
2 tablespoons freshly ground black pepper
Freshly grated nutmeg
1 tablespoon each chopped fresh rosemary and sage
3 cups dry white wine
Directions
Pound the butterflied breasts to flatten, then season with salt and pepper and refrigerate.
Preheat oven to 400°F.
In a 12- to 14-inch sauté pan, heat 3 tablespoons of the oil over medium-high heat until smoking. Add the pancetta and cook until golden brown, 7 to 9 minutes. Add the pork and cook until it starts to brown in its own fat, about 25 minutes, stirring regularly. Drain all but 4 tablespoons of the fat from the pan and add the prunes and chestnuts. Continue cooking for 8 minutes, until the prunes really start to soften. Remove from the heat and allow to cool, about 20 minutes. Add the bread crumbs, Parmigiano, eggs, pepper, nutmeg, and herbs and just bring together, stirring with your hand. (Overmixing here can result in a lead torpedo for a stuffing, so don't do it.)
Place the two turkey pieces on a cutting board skin side down and divide the stuffing between them. Roll each of the breasts like a jellyroll and tie them firmly in several places with butcher's twine. Place the two rolls on a rack in a roasting pan, skin side up. Pour 2 cups of the wine over them, season with salt and pepper, and roast until dark golden brown outside and a meat thermometer reads 165° at the fattest part of the breast, about 1 hour, plus or minus 10 minutes. Remove and allow to rest 15 minutes before carving.
Add the remaining cup of wine to the roasting pan and deglaze, scraping with a wooden spoon. Cook for 5 minutes, then add the remaining 1/4 cup of oil. Shake the pan to emulsify the sauce and season with salt and pepper.
Carve the roast into 1/2-inch slices and drizzle with the pan sauce.
