Stir together, in small bowl, reserved juice, water, 1/3 cup soy sauce, 1 tablespoon cornstarch, red pepper (if desired) and garlic powder; set aside.
Combine chicken with remaining 1 tablespoon each cornstarch and soy sauce, in medium bowl.
Heat oil in wok or nonstick large skillet over medium-high heat. Add chicken and stir-fry 4 to 5 minutes or until lightly browned; remove. Add broccoli, bell pepper, carrot and ginger; stir-fry 4 minutes or until just tender. Add reserved soy sauce mixture and chicken; cook, stirring, 2 to 3 minutes or until sauce boils and thickens. Stir in pineapple chunks and dragon fruit and heat through. Serve over rice.