Rub steaks on both sides with Chimichurri sauce, then sprinkle with salt and pepper.
Heat grill to high.
Place the steaks on the grill and cook until browned and slightly charred, 4 to 5 minutes.
Turn the steaks over and continue grilling for 3 to 5 minutes for medium-rare (an internal temperature of 135 degrees F), 5 to 7 minutes for medium (140 degrees F) or 8 to 10 minutes for medium-well (150 degrees F).
Tent loosely with foil and let rest 5 to 10 minutes before serving.
Serve with extra Chimichurri sauce for topping.