Place noodles in a pot of hot water and let them soak for about a minute. Use your fingers to gently separate noodles. Drain and rinse with cold water. Set aside.
Season sliced chicken with salt and pepper. Set aside.
Combine all the sauce ingredients in a small jar and shake vigorously to combine. Set aside.
Heat 1 tablespoon oil in a wok or large skillet over medium high heat.
Add the sliced chicken to the pan and stir until cooked through, about 2-3 minutes. Remove from the pan and set aside.
Add another tablespoon of oil to the skillet. Add mushrooms and cook until they release all their liquid. Continue to cook until liquid has evaporated and mushrooms begin to brown along the edges, about 5-8 minutes. Remove from pan and set aside.
Add onion, cabbage, garlic, and carrots to the skillet and cook stirring frequently, for 2-3 minutes.
Add red bell pepper and cook for an additional 2-3 minutes.
Add the cooked chicken, mushrooms, noodles, white part of the green onions, and sauce to the pan. Stir to combine.
Cook for 2-3 minutes until sauce coats all the ingredients, is soaked up by the noodles and the sauce no longer pools at the bottom of the pan.
Serve immediately garnished with the reserved green part of the scallions.