In a shallow glass bowl, combine orange juice and cornstarch; mix well. Stir in chicken. Cover and chill for 2 hours.
Drain chicken; discard juice mizture. In a small bowl, combine broth ans soy sauce. Set aside.
In a wok or large nonstick skillet, heat oil over medium heat. Add garlic and ginger; stir-fry for 30 seconds. Add chicken; sir-fry for 3 minutes. Add vegetables; stir-fry until crisp-tender, about 5 minutes. Stir in broth mixture.
Place 1/2 cup of rice on each serving plate. Top with the chicken mixture, dividing evenly.