1 lb. beef round tip steaks, cut 1/8 to 1/4 inch thick
1 (16 oz.) pkg. frozen vegetable mixture with broccoli and red peppers
1/4 c. water
2 tsp. cornstarch, dissolved in 1/3 cup water
3 c. hot cooked rice
1/4 c. chopped, toasted walnuts (optional)

Marinade:

3 tbsp. soy sauce
2 tsp. dark sesame oil

In a medium bowl, combine marinade ingredients. Remove 2 Tbsp; set aside. Stack beef steaks; cut lengthwise in half and then crosswise into 1 inch wide strips. Add beef to remaining marinade in bowl; toss to coat. Heat large nonstick skillet over medium-high heat until hot. Add beef, one-half at a time, and stir fry 1 minute or until outside surface is no longer pink. Do not overcook. Remove from skillet, keep warm.

In same skillet, combine vegetables and 1/4 cup water; cook 4 to 5 minutes or until water is almost evaporated and vegetables are hot, stirring occasionally. Combine cornstarch mixture and reserved marinade; add vegetables. Cook and stir 1 minute or until sauce is thickened and bubbly. Return beef to skillet; heat through. Serve over rice, sprinkle with walnuts if desired.