In a bowl, marinate the sliced beef with light soy sauce, Shaoxing wine, and cornstarch for 15 minutes.
Gently separate the fresh rice noodles into individual strands, taking care not to break them.
Heat 1 tablespoon of oil in a wok over high heat until smoking.
Sear the beef in the wok until browned on the outside but still slightly rare in the center, then remove and set aside.
Wipe the wok and heat the remaining 2 tablespoons of oil.
Add the rice noodles to the wok and stir-fry for 2 minutes until softened and beginning to char.
Incorporate the dark soy sauce, oyster sauce, and sugar, tossing the noodles until they are evenly colored.
Return the beef to the wok and add the bean sprouts and scallions.
Toss all ingredients over high heat for 1-2 minutes until the sprouts are just wilted.
Drizzle with toasted sesame oil and serve immediately.