Coat grill pan with no-stick cooking spray. Heat over medium heat.
Combine olive oil, lemon juice, Italian seasoning, garlic salt, and pepper, in a medium microwavable bowl. Microwave on HIGH for 1 minute. Stir. Dip chIcken in olive oil mixture to coat evenly.
FOR INSIDE COOKING: Place on hot grill pan. Cook 6-8 minutes per side until juices run clear and thermometer reads 165 degrees. Allow to rest 5 minutes before serving.
FOR OUTDOOR GRILL: Coat unheated grill grate with no-stick cooking spray. Preheat grill to medium-high heat. Grill chicken 6-8 minutes per side until juices run clear and thermometer reads 165 degrees F. Allow to rest 5 minutes before serving.