1 package (16 ounces) frozen Asian vegetable blend (such as broccoli, carrots and sugar snap peas)
1/4 cup water
2 teaspoons vegetable oil
3 cloves garlic, minced
2 teaspoons sesame seeds (optional)
Cut beef steak lengthwise in half, then crosswise into 1/8-inch thick strips. Place beef and 1/4 cup stir-fry sauce in food-safe plastic bag; turn beef to coat. Close bag securely and marinate in refrigerator 30 minutes to 2 hours.
Heat large nonstick skillet over medium heat until hot; add vegetables and water. Cover and cook 7 to 8 minutes or until crisp-tender, stirring occasionally. Remove vegetables; keep warm.
Remove beef from marinade; discard marinade. Heat 1 teaspoon oil in same skillet over medium-high heat until hot. Add 1/2 of beef and garlic; stir-fry 1 to 2 minutes or until outside surface of beef is no longer pink. (Do not overcook.) Remove from skillet. Repeat with remaining oil, beef and garlic.
Return vegetables and beef to skillet. Stir in remaining 1/2 cup stir-fry sauce; cook and stir 1 to 2 minutes or until heated through. Garnish with sesame seeds, if desired.