Take the marinated chicken out of the fridge, 15-20 minutes prior to cooking.
Grill the chicken over medium heat, or cook your chicken in a heavy-bottomed pan over medium heat, about 4-5 minutes each side, until cooked through and a meat thermometer inserted in the center reads 165 degrees f.
Allow chicken to rest for 5 minutes before slicing it.
Serve with remaining (untouched) chimichurri sauce and enjoy!