01 - Combine sliced beef with soy sauce, cornstarch, Shaoxing wine, and oil. Mix thoroughly and let marinate for 10-15 minutes to tenderize.
02 - Whisk together light soy sauce, dark soy sauce, oyster sauce, sugar, and water in a small bowl until fully incorporated. Set aside for quick access during stir-frying.
03 - Gently separate fresh rice noodles. If refrigerated and stiff, steam or microwave briefly for 30-60 seconds to soften without overcooking.
04 - Heat 1 tbsp vegetable oil in a large wok over high heat until smoking. Add marinated beef in a single layer and sear for 1-2 minutes until just browned. Remove immediately and set aside.
05 - Add another 1 tbsp oil to the wok. Stir-fry onions and most of the spring onions, reserving a portion for garnish, for 1-2 minutes until fragrant and slightly softened.
06 - Add rice noodles to the wok, spreading them evenly across the cooking surface. Let sear undisturbed for 1 minute to develop slight char and texture.
07 - Pour prepared sauce over noodles and toss quickly using spatula or tongs to coat evenly. The sauce should bubble and reduce slightly, coating each noodle.
08 - Return seared beef to the wok along with bean sprouts. Stir-fry everything together vigorously for 1-2 minutes until all components are heated through and well combined.
09 - Transfer to serving plates immediately and garnish with reserved spring onions. Serve hot while noodles retain their springy texture.