Watercress, Carrot, Dried Duck Kidney, and Pork Rib Soup

Why people make this soup

Most parents know the pattern: a child who loves fried chicken, chips, and meat, eats very little in the way of vegetables — and then starts showing signs of what Cantonese grandmothers would call “too much fire” (热气): bad breath, a dry or slightly hoarse cough, a red throat, yellow urine, or constipation. Western medicine would probably call some of this a minor dietary imbalance; traditional Cantonese food therapy calls it “lung-stomach accumulated heat.”

Watercress is one of the best-known cooling vegetables in Cantonese cooking. Paired with carrot and dried salted duck kidney — a distinctively Cantonese ingredient with a savoury, slightly gamey character — this soup is both genuinely flavourful and traditionally used to clear heat from the respiratory and digestive systems. The long simmer (two hours) ensures the soup is not too cold in nature despite using cooling ingredients.

Method

1. Wash the watercress thoroughly.
2. Peel and cut the carrot into chunks.
3. Soak and rinse the dried tangerine peel.
4. Blanch pork ribs and dried duck kidney together in boiling water for 2 minutes; drain and rinse.
5. Add carrot, dried tangerine peel, dried duck kidney, and pork ribs to a pot with 2.4–2.7 L of cold water.
6. Bring to a full boil, then add the watercress. Once the pot returns to a boil, reduce the heat to medium-low and simmer for 2 hours until reduced to about 1.2–1.5 L.
7. Serve together with the soup ingredients.

Nourilo’s Tips

The key technique here: always add watercress to already-boiling water, never to cold water. Adding it to cold water gives the soup a bitter, astringent edge. Added to rolling boiling liquid, it releases a clean, fresh fragrance that makes the broth genuinely delicious. Once cooked for two hours, this soup is not overly cooling — the long simmering time and tangerine peel both moderate its cold nature — so even the elderly and those with sensitive stomachs can enjoy it.