Ingredients

For the chicken & marinade:

12 ounces boneless skinless chicken breast (sliced into ¼-inch/0.6cm thick slices)
3 tablespoons water
1 tablespoon oyster sauce
1 teaspoon Shaoxing wine (or dry sherry)
1 teaspoon vegetable oil
2 teaspoons cornstarch

For the sauce:

1/2 cup low sodium chicken stock
1/4 teaspoon granulated sugar (or brown sugar)
1 1/2 tablespoons soy sauce
1 teaspoon dark soy sauce
1 1/2 tablespoons oyster sauce
1/2 teaspoon toasted sesame oil
1/8 teaspoon white pepper

For the rest of the dish:

3 tablespoons vegetable oil
2 cloves garlic (chopped)
4 white button mushrooms (or baby bella mushrooms, sliced)
1/2 small carrot (thinly sliced)
2/3 cup celery (thinly sliced)
6 ounces bok choy (cut into ¾ x 2-inch / 2x5cm pieces)
1 tablespoon Shaoxing wine
3/4 cup mung bean sprouts
1 cup snow peas
1 1/2 tablespoons cornstarch (mixed with 2 tablespoons water)

Instructions

Combine the sliced chicken with water, oyster sauce, and Shaoxing wine. Massage the chicken until it absorbs all the liquid. Next, mix in 1 teaspoon oil and 2 teaspoons cornstarch until the chicken is uniformly coated. Set aside.
In a small bowl, mix together all the sauce ingredients, and set aside.
Heat your wok over high heat until lightly smoking, and pour 2 tablespoons vegetable oil around the perimeter. Spread the chicken in a single layer.
Sear for a few seconds, and then stir-fry the chicken for another 15 seconds, or until it is lightly golden brown and opaque. Remove the chicken from the wok and set aside. (It should be about 80% cooked at this point.)
Turn heat back up to high, and add an additional tablespoon of oil along with the chopped garlic. Once the garlic starts to sizzle, add in the mushrooms, carrots, and celery. Stir fry for 20 seconds and add the bok choy. Give everything a good stir and spread the Shaoxing wine around the perimeter of the wok to deglaze it.
Next, stir up your prepared chop suey sauce and spread that around the perimeter to further deglaze the wok. Use your wok spatula to give everything a quick stir.
Once the sauce begins to simmer, add in your bean sprouts and snow peas. Also add the chicken back to the wok. 
When the sauce gets to a strong simmer or boil, mix up your cornstarch slurry. Drizzle it into the sauce, stirring constantly, until it thickens to a consistency you like. Add more cornstarch slurry mix if you like the sauce thicker. Cook for another 10 seconds to ensure everything is coated with the sauce. Serve immediately with steamed rice!