Pierogi

Place of origin: Eastern Europe.

Also known as varenyky, are filled dumplings of East European origin. They are made by wrapping pockets of unleavened dough around a savory or sweet filling and cooking in boiling water.
Pierogi are especially associated with Poland and Ukraine where they are considered national dish.

This one is like those Japanese/Chinese dumpling you are familiar with. But while those Eastern dumpling are usually salty and have chicken or pork in the filling, the pierogi is sour or sweet and doesn't contain meat.