Sol de Mayo has been running in Yanahuara since 1897 and is the standard against which Arequipa's other picanterías are judged. The dining room sits around a large interior patio with palm trees and live música criolla on weekends. The menu is a who's who of regional dishes — rocoto relleno, chupe de camarones, adobo, sopa Americana, ocopa — and all of them are done to a high standard.
This is a lunch place. The restaurant is busiest from 13:00 to 15:30 and quiet by mid-afternoon. Reserve on weekends if you're a group of more than three. The portions are generous and the prices reasonable for the quality. A taxi from the city centre is the easiest way to arrive.