In A Large Nonstick Skillet Coated With Nonstick Cooking Spray, Cook Chicken Over Medium Heat For 10-15 Minutes Or Until Juices Run Clear. Remove And Keep Warm. In A Bowl, Combine The Cornstarch, Broth, Mustard And Honey Until Smooth; Add To The Skillet. Bring To A Boil; Cook And Stir For 2 Minutes Or Until Thickened. Return Chicken To The Pan. Add The Broccoli, Carrot And Onion. Sprinkle With Cayenne. Reduce Heat; Cover And Cook For 7-8 Minutes Or Until Vegetables Are Crisp-Tender.