You can serve your pierogi topped with fried onions and parsley, or you can also try serving them with soured cream, melted butter or fried pieces of bacon.
Look for Polish white cheese at your nearest Polish market, or use cream cheese.
These were delicious! I did find this to be way too much filling for the dough, only used just over half of it, used the rest as calazone filling the next day. As there's only two of us, we now have huge amounts of frozen pierogi for a quick meal! Unlike the original, which took over 2 hours, but was well worth it! - 11 Feb 2012