Combine all ingredients into a bowl, except steak. Add steak and marinate in the refrigerator at least 30 minutes up to overnight. Turning occasionally. Steak can stay in a covered bowl, baking dish or Ziploc bag to marinate.
Preheat grill to medium high heat. Grill to desired doneness, about 6 minutes per side for medium-rare. Allow to sit 5 minutes before slicing. Always slice flank steak against the grain.