Marinate the Beef: In a medium bowl, combine the beef slices with soy sauce, cornstarch, and baking soda. Toss until evenly coated. Let sit for at least 10 minutes while preparing the other ingredients.

Prepare the Sauce: In a small bowl, whisk together light soy sauce, Shaoxing wine, dark soy sauce, sesame oil, sugar, and white pepper until smooth. Set aside.

Cook the Noodles: Follow the package instructions to cook the wide rice noodles until just tender. Drain well, rinse lightly, and set aside to prevent sticking.

Stir-Fry the Beef: Heat 2 tablespoons oil in a large wok over medium-high heat. Add the marinated beef in a single layer. Cook undisturbed for 1–2 minutes per side until browned and tender. Transfer beef to a plate.

Stir-Fry the Vegetables: Add the remaining 1 tablespoon oil to the wok. Add onion slices and sauté for 3 minutes, stirring occasionally. Stir in ginger and garlic, cooking for 1 minute more until fragrant.

Combine Everything: Add the scallions, bean sprouts, cooked noodles, and beef back into the wok. Pour the stir-fry sauce over the mixture. Toss gently but quickly until everything is evenly coated and heated through.

Taste and Adjust: Taste the Beef Chow Fun and adjust seasoning if needed with extra soy sauce or sesame oil.

Serve Hot: Remove from heat and serve the Beef Chow Fun immediately for the best flavor and texture.