What a difference a year makes. Today is Derby Day, the running of the Kentucky Derby horse race, and if I were in Nashville as I was last year at this time—which, thankfully, I am not—I would feel compelled to wear a big hat and make something Southern, and likely a mint julep. But I am in Tucson now, hard by the Mexican border. And today is also Cinco de Mayo, a holiday celebrated throughout America and becoming as popular as Halloween, not least because it is a great excuse, as if one were needed, to eat Mexican food. So Mexican it happily must be.
1 oz grated piloncillo (or light brown sugar, dried)