Use a fork and stab your flank steak at least 25 times, this will help the marinade to absorb.
In a medium bowl combine the remaining ingredients. Mix to dissolve sugars and pour over steak in a zip-lock bag or in a non-reactive pan, marinating as long as possible (not over 24 hours).
Grill meat over medium-high heat on each side for 5 to 7 minutes. To serve, thinly slice meat across the grain on a diagonal. Great served over rice and a salad tossed in soy vinaigrette.
