Cut chicken thighs into bite-sized pieces and place into a mixing bowl.
Add chicken marinade ingredients that will be used for velveting the chicken including 1 tbsp. oil, 2 tbsp. cornstarch, egg white, salt, 1 tsp. sesame oil, 2 tbsp. rice wine vinegar or wine. Allow chicken to marinate in the fridge for 30-60 minutes.
While chicken is marinating, cut up your zucchini, bell pepper, onions, and green onions into small bite-sized pieces.
Prepare your kung pao sauce by whisking together minced garlic, water, soy sauce, rice wine vinegar, brown sugar, oyster sauce, sesame oil, grated ginger, and cornstarch. Set to the side.
Heat wok or large stir fry pan on medium-high heat and add additional 1 tbsp. of oil. Add coated chicken pieces and stir fry until they start to brown on the outside and are almost cooked through, 5-6 minutes.
Remove chicken to a side plate and add final tablespoon of oil. Turn heat to high and add in zucchini, bell pepper, onion, and green onion. Stir fry quickly on high heat for 4-5 minutes and then remove to the side next to the chicken.
To the empty wok, add dried chilis and peanuts and cook until peppers are fragrant (1-2 minutes). The peanuts will get a little color to them as well. Set to the side.
To the same pan, stir in kung pao sauce and allow to thicken and deepen in color for 1-2 minutes.
Add back in chilis, peanuts, vegetables and chicken pieces and stir to coat. Cook for 1-2 minutes and serve.