Heat broth to boiling in 1 1/2-quart saucepan. Stir in millet; reduce heat to low. Cover and simmer 20 minutes.
Meanwhile, spray 12-inch nonstick skillet with cooking spray; heat over medium-high heat. Add vegetables; stir-fry 2 minutes. Stir in 1/3 cup of the apple juice; reduce heat to medium. Cover and cook about 3 minutes or until vegetables are crisp-tender.
While vegetables are cooking, mix remaining 1 cup apple juice, the soy sauce, cornstarch and ginger in small bowl until smooth.
Gradually stir apple juice mixture into vegetable mixture. Heat to boiling, stirring constantly. Boil and stir 1 minute. Stir in chicken; cook until thoroughly heated. Toss with cooked millet.