Marinade cubed chicken breast in all the marinade ingredients for 15 minutes.
In the meantime, prep all the other ingredients for the stir fry, and combine all the Kung Pao Sauce ingredients in a small bowl.
Heat wok or skillet with vegetable oil under medium high heat. Add chicken to wok or skillet. Stir continuously.
Once chicken is almost done, add garlic and ginger and cook until fragrant (do not burn them, ~1 minute). Then add chilies and Kung Pao sauce.
Let the sauce come to a boil, then add zucchini and red bell peppers. Continue to stir for a few minutes until zucchinis are soft.
Add water chestnut, green onions and peanuts. Stir for another minute.
Once everything is cooked, remove from heat.
Serve and enjoy!