In a medium bowl, combine the sliced beef with 1 tablespoon of soy sauce. Marinate for at least 15 minutes.
In a small bowl, whisk together the remaining 1 tablespoon soy sauce, oyster sauce, dark soy sauce, vinegar, sugar, and white pepper. Set aside.
Heat 1 tablespoon of vegetable oil in a large wok or skillet over high heat. Add the marinated beef and stir-fry until cooked through, about 2-3 minutes. Remove the beef from the wok and set aside.
Add the remaining 1 tablespoon of vegetable oil to the wok. Add the minced garlic and stir-fry for 15 seconds until fragrant.
Add the Chinese broccoli and stir-fry for 2-3 minutes until tender-crisp.
Push the vegetables to one side of the wok. Pour the beaten eggs into the empty space and scramble until just set.
Add the wide rice noodles to the wok along with the cooked beef and the prepared sauce. Toss everything together vigorously for 2-3 minutes, ensuring the noodles are evenly coated and heated through.
Serve immediately.
Notes
For best results, use fresh wide rice noodles. If using dried, follow package instructions for rehydration.
Adjust the amount of chili flakes or sriracha if you prefer a spicier dish.
You can substitute beef with chicken, shrimp, or tofu for a different protein option.
Ensure your wok or skillet is very hot before adding ingredients to achieve a good stir-fry.