I had an errand to run at the Coliseum this morning, and ran the gantlet of taco trucks and stands on Coliseum Way, where there's a Latino flea market on the weekends. I noticed a couple of new additions: inside the market itself there was an upscale looking truck called Tacos With A Twist and farther down the street was the bright green El Sierreno Sinaloaense taco truck . I was going to get a "benchmark" carnitas taco from several of them, but changed my mind when I approached the El Sierreno Sinaloaense truck.
When I saw "Sinaloaense" I wondered if they had fish tacos. As I walked up I saw that "Mariscos" was painted on the front and the sides and changed my plans, since seafood was obviously the way to go. But as I was pondering what to order I realized the young woman setting up at the table in front of the truck was getting ready to make pupusas on a small freestanding griddle and changed my plans yet again.
I usually am disappointed in pupusas -- I find them too heavy and the fillings bland. These, however, were outstanding with a delicately crisp surface to the tender, fluffy masa. I ordered two cheese but she gave me one with some of the meat filling by mistake and it was a happy mistake because it turned out to be some porky, well-caramelized carnitas (I got my carnitas after all!). She topped it off with a generous tong full of curtido, which was also very good, striking a balance between being slightly pickled and fresh and crisp. There was some hot sauce on a nearby table if you wanted it.
Apparently the regular weekday spot for this truck in on the Oakland Embarcadero near 5th street. I suspect the pupusas are only when they're parked on Coliseum Way on the weekends. Note that at 10:15 they were still in the process of setting up. The trucks in this area tend to shut down by mid-afternoon as well.