Prep the chicken: In a small bowl combine the chicken pieces with the salt, white pepper, garlic powder and water. Mix well and let marinate for 10 minutes. Stir in the cornstarch really well until the chicken is coated and you can no longer see white powder. Drizzle a tbsp of the vegetable oil over the chicken and stir well.
Cook the chicken: In a large wok, heat the remaining 2 tbsp of vegetable oil over medium high heat. Add the chicken, spread it out for even cooking and cook it until it's about 60% cooked through, should take a couple minutes. Transfer the chicken to a plate.
Cook the veggies: If there's no more oil left in the wok, add another tbsp or so of vegetable oil. Add the carrots, mushrooms, water chestnuts, bamboo shoots and white parts of the napa cabbage to the wok and stir fry for about 10 seconds. Add in the garlic and stir fry for another minute. Add in the snow peas, cooked chicken, and napa leaves. Stir fry for another 30 seconds.
Make the sauce: Stir in the shoaxing wine and stir fry for 10 seconds. Add in the salt, sugar, white pepper and stir. Add the chicken broth and cornstarch slurry and stir fry until sauce thickens, another 30 seconds. Lastly, stir in the sesame oil and remove from heat.
Serve: Serve over rice or noodles.