Chinese tamale

A zongzi (粽子) is a traditional Chinese food. It is rice stuffed with fillings (either meat or beans) and wrapped inside a leaf.

Buster picked one up in Chinatown when he visited NYC with his father Bo and Arthur in Postcards from Buster (episode). Buster calls it a Chinese tamale and says it will take 5 hours to cook when Arthur tells him to eat it.