OOOOH that's one of my favorite things I had when I lived in Mexico City. I actually took a day trip to Puela, where mole sauce originated. I ate Mole Poblano in Puebla....
I haven't tried this restaurant for two reasons, the Cantina San Angel wasn't authentic nor was it good and my kids are picky and don't eat Mexican food. There are alot of misconceptions about Mexican food I think, even the local "authentic" restuarants that have great food cater more towards americanized tastes. If you order a "taco" in Mexico City you will be given 2 corn tortillas together with a serving of grilled beef on it-that's it. Spicy comes from sauces. Tacos al Pastor have more ingredients, like onions and cilantro, to go with the pork and corn tortillas. The chilaquiles tempted me, I had them once in Mexico City for breakfast and I loved them but haven't found similar ones in the US. I dunno maybe I'll get a chance to try San Angel Inn someday