1. Make the marinade. Use the flat side of a knife to lightly crush the garlic cloves. Peel them and add them along with the olive oil, salt, and pepper to a gallon-sized freezer bag. Squish around the outside of the bag with your hand to mix the ingredients. Set aside while you prepare the chicken.
2. Pound the chicken. Lay the chicken breasts flat in a single layer and use a meat tenderizing mallet to pound each piece. Try to get each breast to a uniform thickness. If there are small thin pieces around the edges, you can trim those off for perfectly even cooking. I like to leave them and snack on them when they’re done. 🙂 Chef’s treat.
3. Optional: Cut the chicken. If you’re planning to make them into sandwiches, go ahead and cut them into bun-sized pieces. Otherwise, leave them whole.
4. Marinate the chicken. Place the chicken pieces in the bag of marinade. Squeeze out as much air as possible and seal the bag. Massage everything around to coat the chicken. Place in the refrigerator and marinate for at least 30 minutes or up to 8 hours.
5. Prepare the grill. Start with clean grill grates, then oil the grates while the grill is cold. To make it easy, dip a wadded-up paper towel in cooking oil, making sure it is not dripping. Hold the oil-soaked paper towel with tongs and rub the grates. Preheat the propane grill to medium-high with the lid shut. Aim for about 400℉.
6. Grill the chicken. Place chicken on the grill and close the lid. Cook for 4 minutes, then flip each piece and close the grill. Cook for 4 minutes on the second side, then flip again and check the temperature. The minimum temperature for chicken breast is 165℉.If they aren’t done and aren’t getting too brown, cook for another 2 minutes with the lid closed. Then flip, check the temperature, and repeat until they reach 165℉. If the chicken gets too brown before it reaches 165℉, move it off the direct flame to finish cooking. Total time should take between 8-16 minutes.

Rest and serve. Allow the grilled chicken to rest for a few minutes. This will allow the juices to redistribute. At this point, you can sauce it up if you wish.