Prepare Marinated Cucumbers.
Cut beef Flat Iron Steak lengthwise in half, then crosswise into 1/4 inch strips; set aside. Combine Sesame-Soy Marinade ingredients in medium bowl. Place beef strips and marinade in food-safe plastic bag; toss to coat. Close bag securely and marinate in refrigerator 30 minutes.
Meanwhile heat 1/2 cup oil in large nonstick skillet over medium-high heat until hot. Fry 3 wonton wrappers 15 seconds per side or until crispy; drain on paper towels. Repeat with remaining wonton wrappers.
Remove beef strips from marinade; discard marinade. Heat pan over medium heat until hot. Add 1/2 of beef; stir-fry 1 to 2 minutes or until outside surface of beef is no longer pink. (Do not overcook.) Repeat with remaining beef. Evenly divide beef strips over wonton crisps; top beef with 1 tablespoon Marinated Cucumbers and 1/2 teaspoon sesame seeds. Garnish plate with red bell pepper strips, if desired.
Marinated Cucumbers: Whisk together 2 tablespoons sugar and 1/2 cup rice vinegar in medium bowl until sugar is dissolved. Stir in 1 cup diced seeded cucumbers; place mixture in food-safe plastic bag. Close bag securely and marinate in refrigerator 1 hour. Drain cucumbers in large colander; discard marinade.
Nutrition information per serving: 178 Calories; 99 kcal Calories from fat; 11 g Total Fat; 2 g Saturated Fat; 5 g Monounsaturated Fat; 26 mg Cholesterol; 23 mg Sodium; 7 g Total Carbohydrate; 0.5 g Dietary Fiber; 13 g Protein; 1.7 mg Iron; 2.1 mg Niacin; 0.2 mg Vitamin B6; 1.5 mcg Vitamin B12; 4 mg Zinc; 10.8 mcg Selenium;