Ambuyat is made from pouring hot water into ambulung or better known as sago. Sago is derived from a tree trunk, believe it or not. The trunk of a rumbia tree (scientific name, metroxylon), a family of palm trees such as coconuts, are used to make sago. The trees are cut down. Then they are stripped of fronds and other coverings before being cut into several pieces. These cut pieces are stripped of their hard bark. The pieces are then scraped or grated by machine onto a sluice. — The Daily Brunei Resources