le̍k-tāu-kúi綠豆鬼

small and hard mung beans that do not break down

small and hard mung beans that do not break down after a long time of cooking (and are therefore discarded)

English Wiktionary, “綠豆鬼” (CC BY-SA 4.0) — https://en.wiktionary.org/wiki/%E7%B6%A0%E8%B1%86%E9%AC%BC · confidence: Medium (Wiktionary)