Prepare the Sauce: In a small bowl, whisk together the oyster sauce, low-sodium soy sauce, dark soy sauce, white granulated sugar, pepper, and Sriracha. Mix until the sugar dissolves.

Marinate the Beef: In another bowl, combine thinly sliced beef with baking soda, garlic powder, and 1½ tablespoons of the prepared sauce. Let it marinate for 15-20 minutes.

Sear the Beef: Heat 1 tablespoon of oil in a wok over high heat. Add the marinated beef, searing for 1-2 minutes until browned on the outside but slightly pink inside.

Sauté the Vegetables: Wipe the wok clean and add another tablespoon of oil. Sauté the thinly sliced onion and Chinese broccoli for about 3-4 minutes until charred and vibrant green.

Add the Rice Noodles: Introduce the cooked rice noodles and half of the prepared sauce. Toss gently, cooking for another 1-2 minutes until softened.

Combine and Finish Cooking: Add the bean sprouts and green onion tops along with the remaining sauce. Stir for another 1-2 minutes until vegetables are tender yet crunchy.

Combine the Beef and Serve: Return the seared beef to the wok, folding it into the noodle and vegetable mixture. Adjust seasoning and serve hot.