Pork

Bring chicken stock to a boil
Add salt, sugar, sesame seed oil, pepper, hot sauce, vinegar and soy sauce and stir briefly
Add tofu, mushrooms and wood ear mushrooms to the boiling stock
Whisk cornstarch with water to make a slurry and slowly stir into the soup until thickened
Beat an egg and stir it into the soup for about 8 seconds
Ladle soup into bowls and top with pork and spring onions