Rinse dried shrimps under running water; Soak them in water for 15 minutes; Remove them; Fill a bowl with 500ml water; Add the dried shrimps; Leave it for an hour.
Rinse lean pork under running water; Pat-dry them with kitchen paper; Cut into cubes; Marinate it with seasoning (1) for 30 minutes.
Rinse, drain, peel and slice ginger.
Rinse luffa under running water; Peel it with a Y-shaped peeler; Trim a bit off each base; Cut the remaining into chunks.
Fill a stockpot with 2L water; Bring to the boil over a high heat; Add all the ingredients (including 500ml dried shrimps soaking water); Bring to the boil over a high heat; Turn to a medium heat; Cover the pot with its lid; Cook over a medium heat for 30 minutes; Scoop scum off with a perforated spoon; Stir seasoning (2) into the soup; Turn off the heat; Arrange the soup in serving bowls; Ready to serve.