Serious Eats
Piroshky Piroshky at Pike Place Market in Seattle

Piroshky (or pirozhok—but not to be confused with pierogi) are the Russian version of an empanada, calzone, or any other stuffed hand-held pie. Common fillings include poppy seeds, sausage, cabbage, or whatever else the babushkas over the years had lying around.

Smoked Salmon Pate Piroshky
At Piroshky Piroshky in Seattle's Pike Place Market, they add a Pacific Northwest twist with a version that rolls up smoked salmon pate ($4.50). The dill-flecked dough pocket is filled with the soft fish paste. They also have plenty of sweet flavors, like the Apple Cinnamon Roll ($3.70) or Fresh Rhubarb Piroshky ($3).
There don't seem to be any rules on the piroshky shape. Some come in triangles, others in braids, and the most fun to watch through the window—the cinnamon roll-like spirals. Walk by at the right time and you'll see someone on rolling duty. There are also no rules on when to eat them. It's not meal-specific, so basically it's always piroshky time.
Piroshky Piroshky
1908 Pike Place, Seattle WA 98101 (map)
206-441-6068