Pirog

Pirog is a baked case of dough with either sweet or savory filling. The dish is common in Eastern European cuisines. The name is derived from the ancient Proto-Slavic word pir, meaning "banquet" or "festivity". The Russian plural, pirogi (with the stress on the last syllable), should not be confused with pierogi (stress on "ro" in Polish and English) in Polish cuisine, which are dumplings similar to Russian pelmeni or Ukrainian varenyky. Pirogi come in different shapes and forms: they are often oblong with tapering ends, but can also be circular or rectangular. They can be closed or open-faced with no crust on top.

Source: Wikipedia