Preheat your grill to medium-high heat.
In a small bowl, mix together 2 tablespoons of olive oil, salt, black pepper, garlic powder, oregano, and thyme. Rub this mixture all over the flank steak.
In another bowl, combine the chopped parsley, minced garlic, red pepper flakes, and red wine vinegar. Slowly whisk in ½ cup of olive oil until well combined. Set aside.
Place the seasoned flank steak on the grill and cook for about 5-7 minutes on each side for medium-rare, or until it reaches your desired doneness.
Remove the steak from the grill and let it rest for 5 minutes before slicing against the grain.
Serve the sliced steak drizzled with chimichurri sauce.