Teresa Matias told me that to help satisfy her children’s cries for burgers when buns weren’t handy, she would fold a hamburger patty into a tortilla and fry it. Topped with cheese, lettuce, and tomato, it later became a regular menu item at her restaurant, Teresa’s Mosaic Cafe. Apparently, a lot of moms had the same experience, because the beef patty taco has been standard restaurant fare around southern Arizona since at least the mid-1970s.