My all time favorite taco at Pati's is her taco de nopal con huevo. We're talking cactus strips in a tomato sauce with some fried eggs floating in the sauce. You get a fried egg on your taco, a contemporary version of the usual egg and cactus scramble. This stand has a flair for cooking.
From StreetGourmetLA's latest post on Tacos Guisados in Mexico City. Read the entire post. Also, coming soon on TACO from Street Gourmet LA: the groundbreaking series Tacos 101, so stay tuned!