Prepare the noodles according to the package directions (see note).
Cut beef into thin strips, about 2 x 1/4 inch *I used leftover steak, already cooked to medium rare so it only needed to be heated through, but this is a great dish for an economy cut of beef, just make sure you cut it thin.
In a medium bowl, mix sauce ingredients, set aside.
Mix together the 1 T Soy Sauce with 1 T Cornstarch. Toss the beef strips in the soy sauce mixture and marinate for 10 minutes to tenderize (you can skip this step if in a rush). *If using already cooked beef, add beef to Sauce mixture to add at the end of cooking
Place a large skillet or wok over medium-high heat and add vegetable oil and sesame oil.
When the oil is hot, add raw beef strips and stir fry for 2-3 minutes until the beef is no longer pink. *If using leftovers, skip this step and add beef at the end of cooking just to warm.
Add the onions, celery, sliced carrots and pea pods. Stir fry for 5 minutes or until vegetables are tender. Add water chestnuts, ginger, and garlic and cook another 30 seconds.
Add noodles and bean sprouts to the beef/vegetable mixture (if using leftover meat, add now) and toss with the reserved sauce.
Garnish with green onions, peanuts, and serve immediately. You can also add more Sambal and soy sauce to taste.