Heat oil in a large pot on medium heat. Add minced ginger, garlic and saute until fragrant for about 30 sec. Add onion and saute until trasluscent.
Add mushrooms, bok choy, sliced red and green peppers, carrot, celery, chicken stock and water. Bring mixture to boil.
Add vinegar, soy sauce, fennel seeds, chili garlic sauce, salt and pepper and simmer the soup for about 5-7 min.
Then add shrimp and noodles and cook it for further 3-4 min. Do not overcook the noodles
Turn off the heat. Add spring onions and cilantro, serve warm.