Slice chicken into thin strips. Stir oil, cornstarch, salt, sugar, soy sauce and garlic powder together. Pour over chicken and stir to coat evenly, let stand 30 minutes. Stir cornstarch, soy sauce, water and chicken bouillon together, set aside.
Stir-fry chicken in 2 to 3 Tbsp. hot oil until chicken is browned, about 3-5 minutes. Remove from pan or push up the sides of the wok.
Add 1/2 Tbsp. oil, stir-fry vegetables and cook 2 minutes. Combine with chicken, stir fry for 3-5 minutes. Stir in cornstarch mixture, continue to stir until thickened. Sprinkle with cashews.