Hột vịt lộn
Balut is a fertilized developing egg embryo that is boiled or steamed and eaten from the shell. It is commonly sold as street food most notably in the Philippines, Cambodia (Khmer: ពងទាកូន, paung tea kaun) and Vietnam (Vietnamese: trứng vịt lộn, hột vịt lộn). The length of incubation before the egg is cooked is a matter of local preference, but generally ranges between 14 and 21 days.
Source: Wikipedia