Another source of the custom of eating latkes on Chanukah.

If we need to eat something with oil in it--why not simply eat French fries from your local pizza store?  Why specifically latkes or sufganiot?
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 It is said that the word “lat” in Yiddish means patch, and that the reason we eat latkes on Chanukah is to symbolize that the breaches made by the Hellenists in the Bais HaMikdash were only temporarily patched.  Some even refer to “sufganiot” as “latkes” as well, very likely for the same reason.  The latkes teach that although we were able to mend the breach--Chanukah was not the complete salvation; the wars in fact continued for many years afterwards, and therefore the Rabbis instituted the days of Chanukah the following year, as the Al HaNissim concludes, as days which were “LeHodos U’LeHallel LeShimcha HaGadol.”  This is an allusion to the Geulah, redemption, as an ongoing process based upon our relationship with and closeness to HaKadosh Baruch Hu!  Thus, although we are now past the days after [the original] Chanukah, we can continue to strive for the ultimate goal of Chanukah--which is the Geulah Shleimah and the final Bais HaMikdash BeKedusha U’Veteharah (holinesss and purity)!

Source: Hakhel Awareness Newsletter - hakhelusa@gmail.com