1. Place tarragon, thyme, garlic cloves, and black pepper on cutting board; mince to fine paste. Combine herb paste and butter in medium bowl. Set aside.

2. Following illustrations 1 and 2 below, remove skin from breast meat and then remove breasts from bone structure (discard bones or save for stock).

3. Sprinkle entire surface of each breast with 2 teaspoons kosher salt (or 1 teaspoon table salt). After salting, place each breast cut-side up on work surface. Lift tenderloin away from each breast, leaving it partially attached, and spread butter evenly over cut side of each breast. Replace tenderloin. Following illustrations 3 through 5 below, assemble and tie turkey breasts. Place roast on wire rack set in rimmed baking sheet and refrigerate, uncovered, 1 hour.

4. Meanwhile, light large chimney starter filled with charcoal (6 qt, about 100 briquettes) and allow to burn until coals are fully ignited and partially covered with thin layer of ash, about 20 minutes. Build modified two-level fire by arranging all coals over half of grill, leaving other half empty. Sprinkle soaked wood chips (if using) over coals. Position cooking grate over coals, cover grill, and heat rack until hot, about 5 minutes; scrape grate clean with grill brush. Dip wad of paper towels in oil; holding wad with tongs, wipe cooking grate. Grill is ready when side with coals is medium-hot (you can hold your hand 5 inches above grate for 3 to 4 seconds).

5. Rub surface of roast with 1 teaspoon oil and season with pepper. Place roast on grate over cooler side of grill. Cover grill and grill-roast until instant-read thermometer inserted into thickest part of roast registers 150°F, 40 to 60 minutes, turning roast 180°F halfway through cooking time.

6. Slide roast to hot side of grill and cook, uncovered, until roast is browned and skin is crisp on all sides, 2 to 2 1/2 minutes per side (8 to 10 minutes total). Transfer roast to cutting board and let rest 20 minutes. Cut into 1/2-inch-thick slices, removing twine as you cut. Serve immediately.

Serves 6 to 8