Step 1

Heat gas or charcoal grill. Cut 4 (18x12-inch) sheets of heavy-duty foil. Spray with cooking spray.

Step 2

Using sharp knife, cut 4 crosswise slits about 3/4-inch apart in top of each chicken breast, carefully cutting almost to bottom of chicken breast, but not through. Place each chicken breast on center of each foil sheet.

Step 3

Spoon slightly less than 1 teaspoon pesto into each slit in chicken breast. Place 1 mozzarella slice and 1/2 tomato slice in each slit. Sprinkle evenly with Italian seasoning, salt and pepper.

Step 4

Bring up 2 sides of foil so edges meet. Seal edges, making tight 1/2-inch fold; fold again, allowing space for heat circulation and expansion. Fold other sides to seal.

Step 5

Place packs on grill over medium heat. Cover grill; cook 10 minutes. Rotate packs 1/2 turn; cook 9 to 10 minutes longer or until juice of chicken is clear when center of thickest part is cut (at least 165°F). Remove packs from grill. Carefully fold back foil; garnish with fresh basil leaf.