Prepare the chimichurri by mixing olive oil, minced garlic, fresh parsley, red wine vinegar, red pepper flakes, ½ teaspoon salt, and ¼ teaspoon pepper. Set it aside.
Season the steaks with the remaining salt and pepper.
Add a drizzle of olive oil to a heated iron-cast skillet or grill. Cook the steaks on both sides over medium heat until you reach your desired doneness (rare: 120°F, medium-rare: 130°F, medium: 140°F, medium-well: 150°F, and well-done > 160°F).
Serve juicy beef sliced, with some chimichurri sauce on top.