Boil noodles according to package instruction. In a bowl, mix the noodles, salt, and cornstarch. Coat well the noodles. Then deep fry until crispy and golden brown.
Set a wok on high heat, add oil, garlic, ginger, green chili, and celery, sauté it for few seconds.
Now add cabbage, carrots, bell pepper, and green beans. Saute for 30 seconds.
Now add vegetable stock, salt, black pepper powder, soy sauce, red chili sauce, vinegar, and sugar. Mix well and bring it to a boil.
In a separate small bowl, mix well cornstarch and water to make a cornstarch slurry. Then add it to the soup and cook the soup until it becomes thick.