For the chicken:

• 12 ounces boneless skinless chicken breast (or thighs)
• 3 tablespoons water
• 1 teaspoon cornstarch
• 1 teaspoon neutral oil (such as vegetable, canola, or avocado oil)
• 2 teaspoons oyster sauce
• 1/2 teaspoon coarsely ground black pepper

For the rest of the dish:

• 1/2 cup low sodium chicken stock
• 1 tablespoon oyster sauce
• 1 tablespoon light soy sauce
• 1 teaspoon sugar
• 2 teaspoons dark soy sauce
• 1/2 teaspoon sesame oil
• 3 tablespoons neutral oil (divided)
• 2 cloves garlic (finely chopped)
• 1 medium onion (cut into wedges)
• 1 tablespoon Shaoxing wine
• 1/2 bell pepper (any color, cut into 1-inch/2.5cm pieces)
• 1 stalk celery (thinly sliced on an angle)
• 1 teaspoon coarsely ground black pepper
• 1 1/2 teaspoons cornstarch (mixed with 2 tablespoons water to form a cornstarch slurry)