YIELD: 8 Servings
1/4 cup unsalted butter, softened
8 tsp. Dijon mustard
2 Tbsp. chopped fresh thyme
1 tsp. freshly ground black pepper, divided
1/2 tsp. kosher salt
2 (3 1/2-pound) whole chickens
2 cups applewood chips
Combine butter, mustard, thyme, 1/4 teaspoon pepper, and salt in a small bowl.
Remove and discard giblets and necks from chickens. Using a heavy knife or kitchen shears, cut backbones out of the chickens; discard. Open chickens flat, and place on a large cutting board, skin side up. Flatten chickens with the heel of your hand. Starting at the neck, loosen skin from breast and legs. Rub butter mixture evenly under loosened skin. Lift wing tips up and over back. Rub chicken skins with any remaining butter mixture. Cover chickens, and refrigerate overnight.
Prepare grill for indirect grilling. If using gas, heat one side to medium-high and leave one side with no heat. If using a charcoal grill, arrange hot coals on one side of charcoal grate, leaving other side empty. Maintain temperature at 300°F. Pierce bottom of a disposable aluminum foil pan several times with the tip of a knife; add wood chips to pan. Place pan on grill rack over heated side of grill. Heat wood chips for 10 minutes or until chips begin to smoke.
Sprinkle chickens with remaining 3/4 teaspoon pepper. Place chickens, meaty side down, on grill rack coated with cooking spray over unheated side of grill. Cover and cook at 300°F for 35 minutes. Turn chickens over, moving them over direct-heat side of grill. Cover and cook at 300°F for 20 minutes. Gently turn chickens over; cover and cook at 300°F for 10 minutes or until a thermometer inserted into meaty part of thigh registers 165°F. Remove from grill. Let stand at least 10 minutes before serving.