The Rema [O"Ch 670:2] reports a Minhag to eat cheese on Hanukkah. Yet throughout Eastern Europe Potato Latkes caught on instead
The Late Professor Arnold Miller A"H [father of the late R Sheldon Miller A"H and Louis Miller] once explained to me that the switch from cheese to potatoes was due to the poverty in Eastern Europe;
that Potatoes were simply a cheap substitute for cheese.
Shalom and Regards, RRW