Freeze sirloin steak for 30 minutes for easier cutting. Cut beef into thin strips.
Combine marinade ingredients in bowl. Add beef and marinate for 20 minutes.
Heat wok and add 2 T oil. Add shallot, garlic and ground pepper; stir for 10 seconds. Add beef with marinade and stir for one minute. Add bell peppers and bean sprouts; stir for an additional 2 minutes and set aside.
Heat remaining 2 T oil over medium heat. Add noodles and stir constantly for one minute. Add sauce ingredients and cook for 2 minutes, stirring constantly. Add beef and bell pepper mixture; mix well. Stir fry until heated through. Season to taste with more pepper if desired.