Soak Noodles: Soak 200g of dried rice noodles in warm water for 30 minutes to 1 hour.
Marinate Beef: Mix beef with soy sauce, dark soy sauce, Shaoxing wine, baking soda, neutral oil, white pepper, and cornstarch. Let marinate.
Prep Vegetables: Slice onion, green onions, and garlic. Prepare mung bean sprouts if using.
Make Sauce: Combine soy sauce, oyster sauce, dark soy sauce, Shaoxing wine, sugar, and white pepper.
Cook Beef: In a hot wok with oil, sear marinated beef for about 30 seconds per side. Remove and set aside.
Stir-fry Vegetables: In the same wok, add more oil and stir-fry onions, white parts of green onions, and garlic.
Add Noodles and Sauce: Increase heat, add drained noodles and sauce, stir-frying until noodles are coated.
Finish with Vegetables and Beef: Add beef, green onion greens, and bean sprouts, cooking briefly. Finish with toasted sesame oil.
Serve: Adjust seasoning with salt, transfer to a serving plate, and serve immediately.