There aren't many commercial establishments of any kind between Phx metro and Ehrenberg/Quartzsite microplex. There might be some hidden local gems in Quartzsite, but I've yet to stumble upon any of them.
We got some OK food at La Casita Dos in Blythe a few months back. I can't really give a credible report because (1) at the time, I was so hungry that I'm sure anything would have tasted good and (2) I had to choke the food down quickly so that we could get the car moving and the AC running again. I can report that it seemed to be very popular with the locals.
The pickin's are likely to be less slim in the "Desert Cities" area (Indio, Palm Desert, Palm Springs, etc.), which is in the CA board's bailiwick. Good luck.
La Casita Dos
830 W Rice St, Blythe, CA 92225