Add all the marinade ingredients to a quart or gallon sized zip-top bag.
Trim the fat off the chicken and slice them in half lengthwise. Place the chicken in the bag with the marinade and let out most of the air. Seal the bag and massage the marinade to coat all the chicken evenly.
Place the bag with the chicken on the counter and let it marinate for 20-30 minutes.
Add all the ingredients in a mixing bowl and mix thoroughly. Set aside to let the flavors blend.
Heat a medium to large skillet over medium heat.
Take the chicken out of the bag and place the pieces in the skillet. Cook on the first side for about 3 minutes.
Turn the chicken pieces over and pour the leftover marinade over the chicken. Cook for another 2-3 minutes.
Turn the chicken over again to cook the marinade, about 1 more minute or until the chicken is done.
Serve by spooning the chimichurri sauce over the cooked chicken.