1 In a small bowl, whisk cornstarch and cold water until smooth. Stir in the plum sauce, ginger, soy sauce and pepper flakes; set aside. In a large skillet or wok, stir-fry beef in oil until no longer pink; remove and keep warm. 
 
2.  In the same pan, stir-fry the red pepper, broccoli, carrots, onions and garlic until tender. Return beef to the pan. Whisk the plum sauce mixture; stir into skillet. Cook and stir until slightly thickened. Stir in peanuts. Serve over rice if desired. Sprinkle with sesame seeds. 
To Freeze: Freeze in freezer safe container.
To Reheat: Reheat in microwave or on stovetop 
