Carefully remove skin from meat in one piece. If back included with breast cut free along edge of rib cage. Cut the meat free from bones for the two breast halves.
Sprinkle 1 tsp of kosher salt on each side of each breast.
Assemble the breast halves with cut sides together and thick end to thin end. Drape skin over breast halves and tuck ends under. Tie a piece of string lengthwise around the assembly. Tie crosswise strings at the center, at the ends, and fill in between the center and end strings at 1“ spacing.
Place the roast on plate in refrigerator, uncovered for 1 hour.
20 min. prior to cooking start chimney full of charcoal. Create two level fire with all the coals on one side. Install grate, heat for 5 min., wipe down surface with paper towel and vegetable oil.
Rub surface of roast with oil and season with pepper. Place on grill on cooler side. Cover grill and roast for 25 min, turn 180 deg, add additional briquets as needed to maintain fire. Cook until the thickest part of meat registers 150 deg, 60 to 90 min. 8/15/14-90min, 9/21/16-97min.
After reaching 150 deg slide roast to hot side of fire and cook uncovered until skin is crisp on all sides, 8-10 min total.
Transfer roast to cutting board and all allow to rest 20 min. Cut into 1/2” slices, removing twine as you cut.