1. Whisk together first 5 ingredients in a small bowl; set aside.
2. Heat wok over high heat until a few drops of water evaporate immediately. Swirl 2 tablespoons oil in pan to coat. (If using a nonstick skillet, heat oil over medium-high heat.) Add chicken, and cook 2 to 3 minutes on each side or until lightly browned. Remove from pan; cover and keep warm.
3. Heat remaining 1 tablespoon oil in wok over high heat (medium-high, if using a nonstick skillet). Add bell pepper, green beans, and ginger; stir-fry 3 to 4 minutes.
4. Whisk reserved sauce mixture, and add to wok with vegetables. Cook 1 minute or until sauce thickens. Stir in slivered basil and reserved chicken. Sprinkle with cashews; serve with hot cooked rice and sriracha. Garnish, if desired.