Amy M.
Yelp
This is the most authentic Mexican street/cart food I've eaten in the Boston area. Double soft corn tortillas, not overloaded with filling, not overwhelmed by "Americanized" toppings (but you can add them). Just savory meats, onion, cilantro, salsa verde, and a smidge of cheese.
Elotes ("street corn") was an especially good find - this lesser-know treat is still pretty hard to find on the east coast, and El Vaquero's is delicious. They even have Sangria soda (non-alcoholic) which I do not like but is very authentic to the Mexican street food experience : ) This is food made with love, served with great care and pride.
And now for the minor bummer news. The space to eat is really small (only a couple tables). We ate in because we arrived just before a busy period. It was a nice experience but it would be hard to wait around for a table to open, because when it's busy, there isn't a lot of space to hang around and wait. Just be prepared that you might need to take your food to go. On the upside I was glad to see that it was very busy the entire time we were eating - it's a good sign that they picked an affordable amount of space to start and so they're not over-extended on paying for more space than they need. I'd love to see them eventually grow to a slightly larger space.
Also, related to the small space - there's no public bathrooms. This isn't the end of the world, but it can be an inconvenience if you arrive say ... direct from a work commute home. Again, taking food to go solves this problem. This wouldn't keep me from going but it's helpful to know in advance (esp if you have little kids w you)