The first time I traveled to Spain, on a glorious two-week trip with my sister almost two decades ago, I followed an omnivorous diet, which was helpful in the land of jamón Ibérico and gambas al ajillo. The second time, I was vegetarian, so the menu was shorter – but still plenty satisfying: I enjoyed my fill of vegetable paella, escalivada, pan con tomate (sin anchoas, por favor) and, most ubiquitous of all, tortilla española.