Night-Blooming Cereus, Carrot & Lean Pork Soup

Why people make this soup

Ba wang hua — the dried flower of a night-blooming cereus cactus — has a long history in Cantonese kitchens, especially as a warming-weather soup for clearing what people describe as “lung heat”: thick phlegm, persistent cough, or the stuffy-headed feeling that lingers after a cold. The fresh flower is fragrant but quite cooling and makes the broth slippery; drying it reduces that coolness and makes the soup better suited to both adults and children. In traditional practice, this soup is also used to help children who have what is called “phlegm fire nodes” — swollen lymph nodes in the neck associated with excess phlegm.