Went skiing on New Year's Day; El Pastor in Escalon was closed, so we ate lunch next door at the Cantina (Highway 120 just east of the railroad tracks). I would call the food authentic, but timid. I had a beef tamal plate, and the tamale appeared to be homemade, but the sauce had that Dinty Moore taste and there was no heat to speak of.
Wound up eating Mexican again that night in Arnold at the Blue Frog (Highway 4). They were out of pretty much everything. I ordered camarones al ajo -- adequate, but not memorable. A small dish of walnut-sized shrimp in a warm pool of garlic butter. The refritos tasted as if they had been reconstituted from freeze-dried beans. My dining companion had better luck with the clams -- about two dozen small ones, served with garlic butter.
Earlier this week, had a chile verde burrito at Salsa, off East Leland Road in Pittsburg (near Los Medanos College). Grilled tortilla, good beans, large chunks of tender meat, reasonable amount of heat. It cost almost $7, but was actually too big for me to finish. The chips and salsa were good, too.