Skipping the toppings
Pierogi are traditionally served with few toppings, such as melted butter, sour cream, or sautéed onions. However, this does not preclude the addition of sauce or other toppings to a plate of pierogi. In fact, the simple flavor profile of pierogi leaves plenty of room for experimentation. The type of topping you use should be determined by whether your pierogi are savory or sweet.
According to Polonist, simply combining sour cream with chopped herbs such as dill or chives can result in a delicious savory pierogi sauce. For savory pierogi, Tasting Poland suggests pork scratchings, a roux-based gravy, or bacon bits. Simple is best when it comes to sweet pierogi sauce. Polonist suggests that you use sweetened cream, honey, or fruit sauce. The chocolate sauce could also be used. In fact, one restaurant in Krakow, Poland, serves chocolate-dipped strawberry pierogi.