Hi,
You can make them yourself, too. In another life, I spent a lot of time in the Soviet Union. I was frequently gifted with piroshki, which I thoroughly enjoyed.
For the Greater Midwest Foodways Alliance's Road Food symposium this spring, we put Nebraska's runza on the menu. I knew these originated with Germans who immigrated from Russia in the 1800's. I never saw one until I went looking for recipes, when I checked a youtube video on how they were made I knew they were piroshki.
At the Missouri State Fair,
"cabbage rolls" placed second at our Family Heirloom Recipe contest. I knew they were piroshki. I talked to the woman to learn her family came from Nebraska via Russia and Germany.

My favorite tradition was passed down from my great-grandmother on my father’s side. She was born in Germany and then moved to Russia before finally arriving in the United States. Her family made cabbage buns every year on Christmas Eve in celebration of the holidays, and our family has been carrying on that tradition ever since. Each member of the family pitches in each year. Either you are making the dough, making the filling, or stuffing them, but no one gets to hide out while the rest of the family is baking. We have perfected our own holiday baking assembly line, and we look forward to it all year.
Regards,