Antojitos is an unassuming little cafe in Waltham. They have a paper menu, but it doesn't give you all the options. There're signs on the doors and various menus on the walls - basically you just have to know what to order. I'll try to help because it's potentially worth the trouble.
Pork Tamales: These were the best tamales I've ever had, steamed in real banana leaves, with lots of pork and a rich sauce, though the pork was a little chewy.
Pork Gorditas: This was s good. The pork juice and the black bean purée blended together into this beautiful, hot, runny sauce. Worth the mess in the car.
Though the second time I went and ordered a Pork Gordita, it wasn't as soft and thick as the first time, and the pork was chewier. Inconsistency sucks; maybe the trick is somehow to order it to go.
Pork Pupusa: Meh
Torta with Pork: Delicious, on soft bread, lots of mayo and avocado and tasty chicken, though still not the smushed construction I think of as a torta
Atol de Elote: I wanted to try this new-to-me item, and it was a warm, sweet corn drink with, I believe, some nice cinnamon and milk. It'd be great to share with someone on a cold, rainy day.
Make a thing of it by going to Waltham for a movie at the Embassy Cinema and getting food at Antojitos before or afterwards.