1.Stir The Stock, Cornstarch, Soy And Garlic Powder In A Small Bowl Until Smooth. 2.Stir-Fry The Beef In A 10-Inch Nonstick Skillet Over Medium-High Heat Until It'S Well Browned. Add The Peppers To The Skillet And Stir-Fry Until Tender-Crisp. 3.Reduce The Heat To Medium. Add The Stock Mixture To The Skillet. Cook And Stir Until The Mixture Boils And Thickens, Stirring Constantly. Serve Over The Rice.