In a mixing bowl, combine chopped parsley, olive oil, red wine vinegar, minced garlic, red pepper flakes, oregano, salt, and pepper. Whisk until well combined.

Preheat the grill to medium-high heat. Season the ribeye steaks with salt and pepper on both sides.

Place the steaks on the grill and cook for about 4-5 minutes on each side for medium-rare, or until desired doneness.

Remove the steaks from the grill and let them rest for 5 minutes.

Slice the steaks against the grain and serve topped with chimichurri sauce.