The chef and owner of El Papi ages his consommé for six days before serving it. Yes, he calls it aging, as if his birria were a porterhouse steak slowly losing moisture in a temperature- and humidity-controlled room. One afternoon, Zamora-Herrera walked me through the process for making his birria: It involves braising brisket for hours, removing the meat and using the beef stock as the base for the consommé, which is carefully developed with more than 20 spices, herbs and other ingredients, including ground annatto seeds, ginger and banana leaves fried briefly in brisket fat. Oh, by the way, Zamora-Herrera likes to leave most, if not all, the fat in the stew. No skimming in his kitchen.