Rinse bitter melon; Trim a bit off each base; Cut it into halves; Scrape out the seeds; Cut the remaining into slices.
Rinse, drain and slice ginger.
Rinse pineapple flesh under running water; Drain it; Cut it into pieces.
Rinse a whole chicken under running water; Discard any innards and any lumps of fat from the chicken’s cavity; Remove any feather with a pair of tweezers; Rinse it under running water again; Drain it.
Fill a deep pan with water; Add the ginger; Bring to the boil over a high heat;
Scald the chicken 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; Cut it into pieces.
Fill a stockpot with 2.5L water; Bring to the boil over a high heat; Add all the ingredients, and 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 a serving round terracotta pot; Ready to serve.