In a small bowl, combine the olive oil, lime juice, lime zest, chopped cilantro, minced garlic, salt, pepper, and crushed red pepper flakes. Whisk together really well.
Place the chicken in a large baking dish and then pour the marinade over the chicken. Toss to coat the chicken completely in the marinade.
Cover with foil and place in the refrigerator. The longer that you marinate the chicken, the more flavorful it will be. I’d recommend at least 4 hours up to overnight.
When ready to cook the chicken, preheat grill to medium-high heat. Pour some olive oil onto a paper towel. Use a pair of tongs to brush the oiled towel of the grill grates to grease them.
Cook the chicken for 5-8 minutes per side, depending on the thickness of the chicken. Chicken is done when it reaches an internal temperature of 165 degrees.
Optional: Serve the chicken with extra lime wedges on the side or top with guacamole. (Recipe for the pictured guacamole listed above)