In a large resealable bag, add all of the ingredients. Squeeze out all of the air and seal. Refrigerate for 4 hours or overnight.
When ready to cook, preheat grill on high heat. Grill the flank steak (discard the marinade) 3-5 minutes each side, depending on thickness. Let rest of cutting board for 10 minutes.
Slice across the grain into thin slices and serve immediately.