1. In a medium-sized bowl mix all of the marinade ingredients together. Place flank steak into a 1-gallon resealable bag. Pour marinade over flank steak. Seal bag removing as much air as possible.
2. Marinate overnight in fridge turning bag over a couple of times to ensure even distribution of the marinade.
3. Preheat grill to medium-high heat. 375-450F
4. Remove Flank steak from marinade. Discard the remaining marinade. Grill flank steak to rare/ medium-rare (130E-135F). Remove from grill and rest for 10 minutes. Flank steak must be cut across the grain when serving. I like to sprinkle the slices with a really good kosher or sea salt just prior to serving.