Pierogi are a classic of Polish cuisine, but also of many other Eastern European cuisines. There are dozens of different fillings, sweet or savory. I myself am a big fan of the sweet version with blueberries, covered with cream and sugar. My mother used to spend hours making Pierogi to satisfy my insatiable appetite for them.
My children, however, love the hearty version with meat. The addition of grated grana padano cheese is a tribute to our second culinary love, Italy.