Prep Time: 25 minutes
Cook Time: 10 minutes
In small bowl, combine vinegar, sugar, lime juice, salt, pepper flakes and pepper; mix well. Cover and refrigerate until ready to serve. Heat oil in large skillet over medium heat until hot. Panfry steak in hot oil 4 minutes per side for rare or to desired doneness. Transfer to carving board; season with salt and pepper to taste, if desired. Let stand 20 minutes. Carve across the grain into thin slices. In large bowl, combine spinach, endive, lettuce, corn, tomatoes, green onions and steak; toss lightly. Add dressing; toss again. Add cheese and tortilla chips; toss lightly.