Soak frozen conch meat in water for a couple hours (change water every hour); Cut off any operculum, which is a shell-like covering that protects the conch and assists in locomotion, with a cook’s knife; Cut off and discard the dark tail and stomach, which is near the middle; Pull off the leathery skin; Rinse it under running water again; Drain it.
Rinse and drain American ginseng slices.
Rinse, drain and slice ginger.
Rinse snow pears; Drain them; Twist off any stems; Insert the sharp tip of a swivel peeler and run around the cores of the pears; Scrape out the cores inside; Cut the pears into chunks.
Rinse lean pork; Pat-dry them with kitchen paper; Cut it into trunks.
Fill a deep pan with water; Add the ginger; Bring to the boil over a high heat; Scald the conch meat all over a in a colander with the boiling ginger water for 2 minutes; Immediately remove the conch meat; Scald the lean pork all over in a colander with the boiling ginger water for 3 minutes; Immediately remove it; Rinse it under running water till cool; Drain it; Turn off the heat.
Fill a stockpot with 2.8L water; Bring to the boil over a high heat; Add all the ingredients; Bring to the boil over a high heat again; Turn to a low heat; Cover the pot with its lid; Cook over a low heat for 2 hours; Scoop scum off with a perforated skimmer; Stir seasonings into the soup; Turn off the heat; Arrange the soup in serving bowls; Ready to serve.