Rinse dried scallops under running water; Soak them in water for 15 minutes; Remove them; Fill a bowl with 250ml water; Put the dried scallops in the bowl of water; Leave it for 3 hours.
Rinse dried shiitake mushrooms under running water; Soak them in water for 15 minutes; Remove them; Fill a bowl with 250ml water; Put the dried shiitake mushrooms into the bowl of the water; Leave it for 3 hours; Remove and drain them; Discard the stems with a pair of kitchen scissors; Cut the remaining into pieces with a vegetable knife.
Rinse winter melon under running water; Scrape out the seeds; Peel it with a Y-shaped peeler; Cut it into chunks.
Rinse minced pork under running water; Drain it; Put it in a big mixing bowl; Add seasoning (1); Stir it clockwise until sticky (about 10 minutes); Cover the bowl with cling film wrap; Chill it in the fridge for 1 hour; Take the bowl out of the fridge; Discard the cling film wrap; Stir it clockwise again for 1 minute; Put a portion of the pork mixture on a hand and roll it into a ball (repeat this process till the pork mixture is used up).
Fill a stockpot with 2L water; Bring to the boil over a high heat; Add all the remaining ingredients (including 250ml dried scallops soaking water and 250ml dried shrimps soaking water) and bring to the boil over a high heat again; Turn to a medium heat; Cover the pot with its lid; Cook over a medium heat for 45 minutes; Scoop scum off with a perforated skimmer; Stir seasoning (2) into the soup; Turn off the heat; Arrange the soup in serving bowls; Ready to serve.