He used a variation of the recipe here (http://farmflavor.com/cilantro-lime-chicken/), but i've written it out for you all too!
Juice from ~6 limes
Salt and pepper as desired
1 tsp crushed red pepper
2 tsp minced garlic
1/2 cup chopped cilantro
1/2 cup olive oil
6 boneless, skinless chicken breasts
1. Place chicken breasts in ziploc bag or tupperware container.
2. Mix marinade ingredients and pour over chicken. Marinate at least 2 hours or overnight.
3. Remove chicken breasts and grill until juices run clear or chicken reaches 170 degrees on a meat thermometer.