Prep the chicken. If using chicken breasts, slice them horizontally to make thinner cutlets or pound them to an even 1/2-inch thickness.
This helps them cook quickly and evenly. Pat dry with paper towels.
Make the marinade. In a bowl, whisk together olive oil, lemon zest, lemon juice, garlic, rosemary, thyme, parsley, honey, salt, black pepper, and red pepper flakes if using.
Marinate. Add the chicken to a zip-top bag or shallow dish and pour the marinade over it. Turn the pieces to coat well.
Refrigerate for at least 30 minutes and up to 8 hours. If you’re short on time, even 20 minutes will help.
Preheat the grill. Heat a gas or charcoal grill to medium-high (about 400–450°F). Clean and oil the grates to prevent sticking.
For an indoor option, use a grill pan over medium-high heat.
Grill the chicken. Shake off excess marinade and place the chicken on the grill. Cook for 4–6 minutes per side, depending on thickness, until the internal temperature reaches 165°F. Avoid moving the chicken too much to get good grill marks.
Rest and finish. Transfer to a plate, tent loosely with foil, and rest for 5 minutes so the juices redistribute.
Squeeze fresh lemon over the top and sprinkle with a bit more chopped parsley.
Serve. Pair with a simple salad, grilled vegetables, or rice. Add lemon wedges on the side for extra zing.