The bread is dipped in guajillo chile sauce and then fried, so the sandwich arrives stained deep red on the outside before it's even opened.
A soft roll is soaked in a guajillo chile sauce, fried on a griddle until crisp, and split open around a filling of spiced potato and chorizo, topped with lettuce, crema, and queso fresco. Street stands throughout Mexico City serve them as an affordable, filling lunch.