1. Combine dressing ingredients in large bowl; whisk until blended. Place beef steak and 3/4 of dressing in food-safe plastic bag; turn steak to coat. Close bag securely and marinate in 6 hours or as long as overnight.
2. Meanwhile, add coleslaw mix, 1/2 cup green onions, 1/8 teaspoon salt and dash of pepper to remaining 1/4 of dressing in bowl; toss. Set aside. Wrap tortillas in aluminum foil.
3. Remove steak from dressing; discard dressing. 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. A few minutes before steak is done, place tortilla packet on grid near edge of grill to heat.
4. Season steak with salt and pepper, as desired; carve diagonally into thin slices.
5. 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.