Step 1

Prepare a grill for medium indirect heat: For gas grills (with 3 or more burners), turn all the burners to medium-high heat; after about 15 minutes turn off one of the middle burners and turn the remaining burners down to medium. For charcoal grills, bank one chimney starter-full of lit and ashed-over charcoal briquettes to one side of the grill. Set up a drip pan on the other side to avoid flare-ups (see Cook's Note).

Step 2

To spatchcock the chicken, use strong kitchen scissors or poultry shears to cut down both sides of the backbone. Pull out the backbone, turn the chicken over and press down firmly on the breast to flatten it out to one thickness. Set aside at room temperature (see Cook's Note).

Step 3

Combine the butter, parsley, chives, garlic, shallot, lemon zest, 2 teaspoons salt and 1/4 teaspoon pepper in a medium bowl.

Step 4

Starting at the neck, gently slide your fingers under the skin of the chicken to loosen it from the breast meat. Continue to slide you hand down and loosen the skin around the legs, taking care not to tear it. Rub all but 1 tablespoon of the butter mixture under the skin, spreading it all the way down to the legs. Rub the outside of the chicken with the remaining 1 tablespoon of butter.

Step 5

Place the chicken skin-side up on the indirect-heat area of the grill with the legs facing the hotter side. Cover the grill (the lids vents should be partially open) and cook until an instant-read thermometer inserted in the thickest part of the thigh (avoiding the bone) measures 150 to 160 degrees F (almost cooked through), about 50 minutes.

Step 6

Transfer the chicken to the direct-heat area of the grill. After 2 minutes, flip the chicken to char and crisp up the skin side, another 3 to 4 minutes. Check that the temperature in the thigh is now at least 165 degrees F when not touching bone. If not, move the chicken back to the indirect area, skin-side up, cover and cook until the final temperature of 165 degrees F is reached.

Step 7

Remove the chicken from the grill to a cutting board; let rest 20 minutes before carving.