Food of the Elves?

[Kuruharan]

The thing is, he didn't write about it very much. Maybe he didn't think it was important aspect of the stories. Also, his stories center around kings and warriors, a farming elf doesn't have any place in his works.

That is very true. The only glimpse that we have of elves outside of the circles of power or warfare are the raft-elves in the Hobbit. (That job must have gotten very boring after a few thousand years. I wonder if there was some sort of work rotation system among the elves, to make sure that the essential jobs were done but that nobody got bored from doing it for eternity.)

Since lembas is described as a wafer, I think that we can also assume that they grew grains of some sort.

So I submit that Elves had a truly advanced form of agriculture where only a few had to work and they could exploit very little land and still have a bountiful harvest able to feed all the Elves of the given kingdom, along with supplemental food from hunting and gathering and any domestication of animals.

It could also be that since Elves had a special relationship with living and growing things they did not need to expend too much energy farming.