A traditional Polish dish. Imagine a bowl of warm vinegar filled up with diced sausage and cabbage.
Only if it's made by incompetents!
My great auntie/granny used to make their own versions (there is no one correct recipe) and it was not vinegary at all! And they used bacon as well as sausage....
And the cheese and potato pierogi are lush, imagine massive ravioli (but much stodgier dough/pasta) served with melted butter or sour cream and that's about what you should get!
MMM yum!