1. Soak cloud ear and shiitake mushrooms till softened, then thinly shred; dice scallop; shell tiger prawns then dice; rinse, peel and dice carrot, set aside.
2. Bring a pot of water to boil, blanch corn for 1-2 minutes, drain; blanch carrot for 4-5 minutes, drain; blanch cloud ear and shiitake mushroom for 3 minutes, drain.
3. Heat oil in a wok, sauté prawn and scallop till cooked, set aside.
4. Boil chicken stock in a large pot, season with sugar, salt and chicken powder, then slowly thicken with corn starch and water mixture.
5. Toss all the ingredients into the soup, turn heat off when it boils, slowly pour in egg white and stir.
6. Add a pinch of black pepper and garnish with chopped coriander, serve.