In a mixing bowl, combine the chicken pieces with 1 tsp light soy sauce, 1 tbsp rice wine, 1/4 tsp dark soy sauce, 1/8 tsp baking soda, 1/4 tsp garlic powder, 1/4 tsp black pepper, 1 tsp cornstarch, and 15 ml water. Stir well to coat all pieces evenly. Marinate for 10 minutes to tenderize and flavor the meat.

Heat a wok or large skillet over high heat and add enough oil to coat the base. Add the marinated chicken in a single layer. Let it sear undisturbed until the underside is golden brown (about 2-3 minutes). Flip and cook until the chicken is roughly 80% cooked through.

If needed, add a little more oil, reduce the heat to medium, and add the mushrooms. Cook until the bottom side browns nicely, then stir or flip to brown the other side as well (about 4-5 minutes). The mushrooms should be tender and lightly caramelized.

While mushrooms cook, prepare the sauce by mixing 1 tsp light soy sauce, 1 tsp oyster sauce, 1/2 tsp sugar, 1/4 tsp black pepper, 1/2 tsp cornstarch, and 60 ml water in a small bowl until smooth.

Add the minced garlic to the mushrooms in the pan. Stir-fry for 30 seconds or until the garlic is aromatic but not burnt.

Return the chicken to the wok. Pour in the sauce mixture, then increase the heat to high. Toss everything quickly and continuously until the sauce thickens and coats all ingredients evenly (about 1-2 minutes).

Add chopped scallions if using, stir briefly just to soften, and remove from heat immediately.

Serve hot for best texture and flavor.