Combine all marinade ingredients in a large mixing bowl and whisk together.
Cut across the flap meat to create two inch wide steaks, and place them into a sealable bag.
Reserve ½ cup of marinade for dipping sauce, and pour the rest over the steak. Ensure the entire surface of the meal is covered. Squeeze excess air from the bag before sealing.
Place the bag on a plate to catch any leaks and place it in the refrigerator for at least 30 minutes, but 4-6 hours is preferred.
Light your grill and prepare it for direct high heat cooking.
While the grill is preheating, remove the steaks from the marinade and pat dry. Remove as much marinade from the surface as possible as the sugar in the marinade will burn easily.
Place the steaks directly over the heat and grill for about two minutes per side, flipping every 60 seconds.