In a mixing bowl, combine the boneless skinless chicken breast, water, oyster sauce, cornstarch, and vegetable oil. Massage the marinade into the chicken and let it rest for 10 minutes.

In a separate bowl, mix the low sodium chicken stock, sugar, soy sauce, dark soy sauce, sesame oil, and white pepper. Stir until the sugar dissolves completely.

Bring a pot of salted water to a boil and blanch the broccoli for 1-2 minutes. Drain and transfer to an ice bath.

Heat a large wok or skillet over high heat and add vegetable oil. Add the marinated chicken and sear for 3 minutes.

In the same wok, add garlic and ginger, and sauté for 30 seconds.

Pour the prepared sauce mixture into the wok, bring it to a simmer, and cook for 2-3 minutes.

Mix cornstarch with water to create a slurry and drizzle it into the simmering sauce while stirring until it thickens.

Return the seared chicken and blanched broccoli to the wok, and toss gently in the thickened sauce.

Taste and adjust seasoning before serving hot over fluffy steamed rice.