1. Cut beef steak lengthwise in half, then crosswise into 1/8-inch thick strips. Combine beef and 1/3 cup stir-fry sauce in large bowl; toss to coat. Cover and marinate in refrigerator 30 minutes to 2 hours.
2. Heat 1 teaspoon oil in large nonstick skillet over medium-high heat until hot. Add vegetables; stir-fry 1 minute. Add water; reduce heat to medium. Cook, covered, 2 to 3 minutes or until vegetables are crisp-tender, stirring occasionally. Remove from skillet; keep warm.
3. Remove steak from marinade; discard marinade. Heat remaining 1 teaspoon oil in same skillet 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.) Remove from skillet. Wipe out skillet with paper towel. Repeat with 1 teaspoon oil and remaining beef. Return all beef and vegetables to skillet. Stir in remaining 1/3 cup stir-fry sauce; cook and stir 1 to 2 minutes or until heated through.