I've been visiting Palm Desert for a couple years with extended family, and finally found a Mexican restaurant I really enjoyed: Salsas Restaurant (aka Taco Salsas). It's very unpretentious, has little decor and is in a strip mall so this may not be for everyone, but if authentic food is, especially Mexican seafood, it's worth the drive to Cathedral City.
Everything we ordered was tasty but the standouts were the fish taco (not deep fried fish, with shredded cabbage and tomato and creamy sauce) and shrimp tostada (like good shrimp cerveche on a tostada). Maybe the best thing is the salsa/garnish bar where there were about 5 types of salsas, fresh and roasted types of chiles, lime, cilantro, diced onion...... so we cound personalize the flavors of everything (My husband especially loves condiments.).
There's a full bar with a really good slection of tequilas too.
They're open breakfast, lunch and dinner so we'll be going back tomorrow!