1. Heat 2 tbsp. oil in wok over high temperature. Brown 1 slice ginger root and 1 garlic, discard.
2. Stir-fry bean sprouts for 1 minute. Sprinkle some salt, remove.
3. Heat 3 tbsp. oil over high temperature. Brown 1 slice ginger root. Add beef and mushrooms, stir-fry for 2 minutes, remove.
4. Heat 1 tbsp. oil, put in carrot, cook for 1 minute. Add 3 tbsp. oil. When wok is smoky hot, put in noodles, stir-fry quickly and turn heat to medium.
5. Add scallions, bean sprouts, beef and mushrooms. Stir-fry to mix them with noodles thoroughly.
6. Pour in sauce and stir-fry for another minute, serve.