Cut the chicken breasts in half lengthwise, then cut them again at a slight angle into 1/4-inch-thick slices. Transfer to a medium bowl. Add 1 1/2 teaspoons kosher salt, 1/4 teaspoon ground white pepper and 3 tablespoons cold water. Use your hands (wear gloves if you like) to massage the seasonings into the chicken until most is absorbed, about 1 minute. Add 3 tablespoons cornstarch and mix until the cornstarch is moistened. Add 3 tablespoons neutral oil and massage until combined. Set the chicken aside to marinate at room temperature for 30 minutes.

Stir the remaining 2 tablespoons cornstarch and 3 tablespoons cold water together in a small bowl until combined. Set aside.

Heat a wok over high heat until you see the first few wisps of smoke, about 3 minutes. Remove the wok from the heat and add the remaining 3 tablespoons vegetable oil and swirl to coat the wok. Return to high heat and add the marinated chicken. Spread it out evenly so every chicken piece has contact with the wok. Let sit until it starts to brown, about 2 minutes. Toss the chicken with a wok turner or spatula and cook until just slightly pink, about 2 minutes.

Add the grated garlic and ginger to the wok and stir until fragrant, about 30 seconds. Add the broccoli and stir-fry 30 seconds. Add the chicken broth, bouillon powder and sugar and bring to a boil. Taste and adjust the seasoning if needed.

Slowly drizzle the cornstarch slurry into the wok and continue to cook until the sauce thickens and coats the broccoli. Pour the mixture over hot steamed rice and serve immediately.