What to get:
The green pozole!! I wanted to call my mother and her comadre and complain to them that they robbed me of a childhood experience! This isn't on their menu so call ahead and find out if they are serving it that day because it's delicious. The other is the Quesadilla de Huitlacoche (wheat-LA-ko-cheh). Huitlacoche is the fungal, culinary delicacy Ustilago maydis that grows on ears of corn. According to GourmetSleuth.com, "American farmers call it smut and devil's corn and consider it a disease to be irradiated. The peoples of Mexico as well as the American Hopi Indians consider the fungus a delightful delicacy." In NYC they call it Mexican corn truffle... whatever, order it, trust me you won't be disappointed.
What not to get:
Unfortunately I didn't think the tacos were all that, in fact a bit dry. Tacos are very simple yet very difficult to nail. If you make it out to Chavella's you should try some of their other dishes.