We are originally from Tucson, AZ and just relocated to Spokane. Since arriving this winter we have been trying all the mexican restaurants in town and found El Sombrero to serve the most authentic Mexican food. Their machaca was excellent (though I missed the egg that is typical of Machaca in the SW).
Though I prefer chunkier salsa- this type of Salsa is the same that is served at a few of the best restaurants in Tucson (i.e. El Charro), so it wasn't entirely off putting.
The margarita is by far the best in Spokane- the only one that tasted like it was a real margarita and not the premixed stuff that seems to abound up in the NW.
Of course Mexican in the NW is never going to compare to that found in the SW- we will definitely be returning to El Sombrero and are very happy we finally found a good Mexican restaurant in Spokane.
Initially I posted a good-fair review of El Sombrero in April of 2011. However the last two to three visits were increasingly less appetizing. Our final visit was the worst, the service was poor, the chips cold, and the food subpar. I had chilaquiles a couple times previously and this time it was just a soggy mess.
We used to go so I could get a decent margarita and my husband could get a great chimichanga. However, this time the margarita tasted like those you get anyplace else in Spokane- the gross pre-mixed variety- and the chimi was stuffed with beans and very little meat.
I don't know if they hired a new cook who isn't sure what to do with Mexican fare, but it was extremely disappoionting, and we haven't been back since.