Enjoy these Korean-style beef Flat Iron Steak lettuce wraps with pickled vegetables and a flavorful dipping sauce. Garnish with your favorite fixings.
Combine Pickled Vegetables ingredients in medium bowl; tossing gently to combine. Set aside for 30 minutes, stirring occasionally. Squeeze vegetables dry; place vegetables in large mixing bowl. Combine Brine ingredients in medium sauce pan; bring to a boil over medium heat. Carefully pour hot brine over vegetables, making sure to cover completely. Refrigerate until cold.
Filet beef Flat Iron Steak to 1/4 to 1/3 inches thick. Slice beef pieces in half lengthwise; then into 2-inch squares. Combine all Marinade ingredients but onion in food processor base; process until smooth. Place beef, marinade and onion in food-safe plastic bag; turn steak to coat. Close bag securely and marinate in refrigerator for 30 minutes to 2 hours.
Combine Dipping Sauce ingredients in small bowl; mix until thoroughly combined. Cover and set aside.
Soak 4 bamboo skewers in water for 10 minutes; drain. Place two to three slices of onion in center of each piece of beef; roll tightly into a cylinder. Thread beef rolls onto skewers, leaving room between each roll. Place skewers on preheated gas grill, covered, 7 to 10 minutes for medium rare (145°F) to medium (160°F) doneness, turning occasionally. Keep warm.
Drain Pickled Vegetables; discard liquid and arrange on serving platter. Top with beef rolls. Serve with Dipping Sauce. Garnish with mint, cilantro, garlic, and peanuts, sesame seeds and line, as desired.