Mix Cornstarch, Broth, Soy Sauce, Lemon Juice And Ginger Until Smooth. Set Aside. Heat 1 Tablespoon Oil In Medium Skillet Over Medium-High Heat. Add Chicken And Stir-Fry Until Browned And Done. Remove Chicken. Heat Remaining Oil Over Medium Heat. Add Broccoli, Carrots And Onion And Stir-Fry Until Tender-Crisp. Stir Cornstarch Mixture And Add. Cook Until Mixture Boils And Thickens, Stirring Constantly. Return Chicken To Skillet And Heat Through. Sprinkle With Cilantro. Serve Over Rice, If Desired.