In the Merced, the central market of D.F., you can get some banging food.
I went for two Quesadillas- one with chicken and caramelized onion, the other with Flor de Calabeza- Squash Flowers. The Flor had a salty, pungent taste, almost like anchovies. Both Quesadillas had stringy white Oaxacan cheese.
Andrew got some pork tacos which you can then pile up with amazing condiments.