1. Heat a large nonstick skillet over medium-high heat. Add oil to pan; swirl to coat. Add steak to pan; cook 2 minutes, searing on one side. Add bell peppers; cook 2 minutes or until beef loses its pink color, stirring constantly. Remove beef mixture from pan.
2. Add soy sauce, vinegar, ginger, and chili garlic sauce to pan; bring to a boil. Cook 1 minute or until slightly thickened. Add beef mixture and green onions to pan; toss well to coat. Sprinkle with sesame seeds.