Place the skirt steaks in a shallow vessel and coat with one cup of authentic chimichurri. Cover with plastic wrap and place in the refrigerator, allowing them to marinate for 2-4 hours.
Fire up the grill and allow it to preheat to high heat. Then, shake off any excess marinade from the steaks and place them on the grill over direct heat and grill them for 2-3 minutes per side.
Remove steak from grill when desired internal temperature is reached, as indicated by a reliable instant read thermometer. I recommend medium rare.
Allow steaks to rest for three minutes before slicing and serving hot with remaining authentic chimichurri and red chimichurri. Salt and pepper as desired.