http://www.chlopskiejadlo.com.pl/restauracjee.htm
you can even check out the menu online
I had a great meal at this restaurant. I believe I went to the one on Sw.Jana street. right off Rynek (town square), its small and you will love the decor.
It was also voted as the best restaurant in Poland, so reservations are necessary
Enjoy Krakow, its an awesome city!