Combine all ingredients listed (except chicken) into a food processor. Pulse until all ingredients are finely chopped and mixture is smooth.
Pour marinade into a shallow dish and place chicken in dish to marinade for 1 - 2 hours. Flip the chicken breasts once, about half way through the marinade time.
Place a pan over medium high heat and sear the chicken breasts on each side. Should take about 4 - 5 minutes per side. Reserve excess marinade.
After both sides are golden brown, reduce heat to medium low and remove chicken from pan. Put chicken onto a cutting board and slice chicken into strips, about 1/2 inch thick.
Return chicken to pan and add the excess marinade. Stir everything to combine and let simmer for another 3 - 4 minutes, or until chicken is cooked all the way through.
Remove from heat and use chicken anyway you see fit! My favorite way...use chicken for tacos and top with caramelized onions, guacamole, chopped tomatoes, and lettuce!