COAT grill pan with no-stick cooking spray. Heat over medium heat.
COMBINE olive oil, lemon juice, Italian seasoning, garlic salt and pepper in medium microwavable bowl. Microwave on HIGH for 1 minute. Stir.
DIP chicken in olive oil mixture to coat evenly. Place on hot grill pan. Cook 6 to 8 minutes per side until juices run clear and thermometer reads 165° F. Allow to rest 5 minutes before serving.
COAT unheated grill grate with no-stick spray. Heat to medium-high (350° to 400°F.)
GRILL 6 to 8 minutes per side until juices run clear and thermometer reads 165° F. Allow to rest 5 minutes before serving.