Help find fantasy elf book

I tried this a couple of years ago with no results.
There are various entrances to an underground inhabited by elves. They are mean ugly nasty creatures. The protagonist wanders throught the underground world for some time. There is an ‘elf bread’, a fungus that they survive on. It is hallucenogenic. There are swords and various cutlery. People look at tea leaves a lot. I think is is in San Francisco.

Have you tried the elf help section of your local bookstore?