Trim any excess fat and sliver skin off the flank steak.
In a 1 gallon plastic bag, add marinade ingredients. Place flank steak in the baggie and seal. Marinade in the refrigerator for at least one hour, no more than 4.
Grilled Flank Steak
Prepare grill for direct grilling using a good quality lump charcoal. Remove flank steak from marinade and pat dry with a paper towel. Combine the salt and pepper in a small bowl and season the steak with the rub.
Place the flank steak over direct heat and cook for 6 minutes or until a nice crust develops. Flip the steak and cook for another 6 minutes or until the internal temperature reads 125 degrees for rare.
Remove from the grill and let rest for 10 minutes to allow to come up to temperature and to let the cells reabsorb the juices.