In a medium-sized bowl, combine sesame oil, kosher salt, and ground black pepper. Add the diced chicken, covering the pieces as best as possible. Set aside
In a fresh bowl, mix the chicken broth, oyster sauce, hoisin, soy sauce, sesame oil, and cornstarch. Whisk until combined. Set aside.
Heat oil in a wok over medium-high heat
Add the diced chicken breast. Fry until cooked through, about 5 minutes. Set aside.
Reduce heat to medium-low. Sautée the onions for 3-5 minutes, until soft and translucent.
Add garlic, carrots, celery, chopped green onion, and cabbage. Cook for a further 2 minutes.
Add pre-cooked noodles and chicken. Toss ingredients until evenly combined.
Pour chicken broth and hoisin sauce mix over noodles. Add slowly while tossing noodles to ensure even coverage.
Serve into bowls and garnish with extra green onion. Enjoy immediately.