2tablespoonscornstarch(mixed into a slurry with 2 tablespoons water)
Heat your oil to 400 degrees in a deep medium pot. Break up the noodles with your fingers and drop them in the oil a handful at a time. Use a pair of heatproof chopsticks or a long fork to break up the noodles and prevent them from sticking together. Fry until golden brown. You may need to flip/move the noodles so they brown evenly. Drain on a paper towel and let cool. Repeat until all noodles are done and set aside.
In a medium bowl, marinate the chicken with the soy sauce, sesame oil, and cornstarch. Set aside while you prepare the other ingredients.
When you're ready to cook, place a wok over high heat. Add a tablespoon of oil and sear the chicken. Remove from the wok and set aside. Add the onions and garlic to the wok and stir-fry for 30 seconds. Then add the celery and mushrooms. Stir-fry for another minute.
Add the bamboo shoots, water chestnuts (if using), napa cabbage, and bok choy. After stir-frying for about 30 seconds, add the seared chicken, chicken stock, salt, sugar, pepper, and bean sprouts. Stir-fry until the mixture comes to a boil.
Gradually stir in the corn starch slurry until the sauce is thick enough to coat a spoon. If you like more sauce, you can add more chicken stock and re-season. Serve over rice. Top the dish with a generous handful of fried noodles and enjoy. Nothin' like takeout food at home!