Combine dressing and chilies. Pour mixture over steak. Marinate in a covered container for at least 6 hours in the refrigerator, turning occasionally. Grill flank steak 3 to 4 minutes per side until done. Slice across grain into thin strips. Assemble Fajitas by placing a few strips on warmed tortilla. Top with lettuce, tomato and cheese. Sprinkle with hot sauce.