Combine the pork with cornstarch, light soy sauce, dark soy sauce, Shaoxing wine, and sugar. Massage the marinade into the pork until it forms a light, creamy coating. Let it sit while preparing other ingredients.

Place the noodles in a bowl and pour hot water (not boiling) over them. Let them sit for up to a minute to release the packet shape. Use chopsticks or a fork to separate the strands gently. Drain immediately to avoid overcooking.

Preheat the wok on high heat until it starts to smoke. Add a tablespoon of oil and swirl to coat the surface.

Add the marinated pork to the wok, spreading it out. Sear for 30 seconds to 1 minute without stirring to develop a crispy edge. Flip and cook until browned. Remove and set aside.

Add another tablespoon of oil to the wok. Add the mushrooms and cook on high heat without stirring initially to seal in moisture. Once the edges brown, stir-fry briefly. Remove and set aside with the pork.

Add a small amount of oil if needed. Toss the choy sum or bok choy into the wok. Stir-fry for 1-2 minutes until slightly wilted. Remove and set aside.

Add the last tablespoon of oil to the wok. Toss in the prepared noodles, spreading them out across the wok's surface. Add light soy sauce, dark soy sauce, and sugar. Stir to coat the noodles evenly, ensuring a rich, deep color.

Pour in the chicken stock around the edges of the wok. Stir vigorously to lift any caramelized flavors from the bottom. Add back the pork, mushrooms, and vegetables. Toss everything together until the noodles are tender, and the sauce is absorbed.

Plate immediately while hot and enjoy the rich, smoky flavors of this quick stir-fry.