1: Combine marinade ingredients. Place flank steak and marinade in re-sealable bag and refrigerate 3 hours. Grease BBQ grill and heat to high. Grill flank steak, 3-5 minutes per side, until medium well. Remove from grill and let rest. Slice across the grain. Meanwhile, combine ingredients for both coleslaw and salsa in medium bowls.
2: To assemble, warm corn tortillas on bbq. Top with sour cream, relish, hot pepper rings, steak, coleslaw, salsa and pickles. Serve open faced with additional toppings on the side.