1. Place the whole turkey breast side down on a cutting board.
2. Remove the neck and giblets and set aside to make the turkey stock.
3. With a sharp knife or a pair of kitchen shears, cut the turkey down each side of the backbone, removing it completely. Open the turkey and press it flat on the cutting board.
4. Using a sharp knife, loosen the breast bone from between the turkey breasts and remove it with your fingers. This will enable the turkey to open completely flat.
5. Apply a light coat of olive oil to the turkey skin and liberally season the skin with kosher salt and black pepper.
6. Build a charcoal fire for direct grilling. The heat over the coals should be hot, (approximately 450º to 500℉).
7. Melt the butter in a medium sauce pan. Add the remaining fresh herb butter ingredients, mix well, and keep warm until needed.

To make turkey stock

1. Add 3½ cups water, 1 ¾ teaspoons salt, turkey neck and giblets to a medium sauce pan. Bring to a boil. Reduce the heat to medium-low, cover, and simmer for 1½ hours.
2. Place the butterflied turkey directly over the coals, skin side down, and baste with the fresh herb butter.
3. Grill the turkey for 5 to 7 minutes or until the skin starts to turn golden brown and begins to crisp.
4. Transfer the turkey to a 10”x10” baking dish skin side up, place it back on the grill, and baste with fresh herb butter.
5. Cover the grill and close the air dampers reducing the cooking temperature to 350℉.
6. Cook for 2½ hours basting every hour with the remaining fresh herb butter. The internal temperature of turkey thigh should reach 175-180℉ while the breast meat should reach 160 to 165℉.
7. Remove the turkey from the grill, cover it with foil, and let it rest for 15 minutes prior to carving.

To make the gravy

1. Scrape all of the drippings and liquid from the bottom of the roasting pan into a small bowl.
2. Skim the grease from the top of the liquid. Pour the seasoned liquid, about ¾ cup, into a small sauce pan.
3. In a small bowl, whisk the two tablespoons water with the cornstarch until smooth.
4. Add the cornstarch slurry and two cups of the pre-made turkey broth to the sauce pan and heat.
5. Serve drizzled over the turkey or on the side as table gravy.