Prepare the Chicken: Start with your thin chicken cutlets. If you haven't already, follow the instructions above to pound your chicken to an even thickness of about 1/4 inch.
Marinate the Chicken: Combine olive oil, garlic, dried herbs and vinegar in a large deep shallow dish. Season chicken on both sides with salt and black pepper then add to the marinade.
Make sure they’re evenly coated then, cover and marinate at least 30 minutes, but preferably up to 2 hours for better flavor. Or as long as overnight.
Preheat Your Grill: Heat your grill or grill pan to medium-high heat. If you're using a charcoal grill, wait until the coals are covered with white ash.
Grill the Chicken: Once your grill is heated, oil the grates and add the chicken cutlets. Grill the chicken for about 2-3 minutes on each side, or until browned and the internal temperature reaches 165°F (74°C). Because the cutlets are thin, they will cook quickly. Be careful not to overcook them, as chicken can become dry if cooked too long.
Rest and Serve: Once cooked, let the chicken rest for a few minutes before serving. This allows the juices to redistribute throughout the chicken, making it more tender and flavorful.