Marinade and Dressing:
Combine Marinade and Dressing ingredients in large bowl; whisk until blended. Place beef Flank Steak and 3/4 of dressing in food-safe plastic bag; turn steak to coat. Close bag securely and marinate 6 hours or as long as overnight. Reserve remaining dressing.
Meanwhile, add coleslaw mix, 1/2 cup green onions, 1/8 teaspoon salt and dash of pepper to remaining dressing in bowl; toss. Cover and refrigerate until ready to serve.
Remove steak from dressing; discard dressing. Pat steak dry with paper towels. Place steak on grid over medium, ash-covered coals. Grill, covered, 11 to 16 minutes (over medium heat on preheated gas grill, 16 to 21 minutes) for medium rare (145°F) to medium (160°F) doneness, turning occasionally. Wrap tortillas in aluminum foil. Place tortilla packet on grid near edge of grill to heat.
Season steak with salt and pepper, as desired; carve diagonally into thin slices.
Arrange equal amounts of beef and coleslaw mixture across center of each tortilla. Sprinkle evenly with 1/3 cup chopped peanuts. Fold bottom edge of tortilla up over filling. Fold right and left sides to center, overlapping edges. Garnish with green onion and additional peanuts, if desired.
Nutrition information per serving: 452 Calories; 171 kcal Calories from fat; 19 g Total Fat; 4 g Saturated Fat; 6 g Monounsaturated Fat; 42 mg Cholesterol; 424 mg Sodium; 41 g Total Carbohydrate; 1.8 g Dietary Fiber; 31 g Protein; 3.5 mg Iron; 7.4 mg Niacin; 0.6 mg Vitamin B6; 1.4 mcg Vitamin B12; 4.4 mg Zinc; 27.5 mcg Selenium;