At Güerrín, they go through 600-700 portions of fainá a day, according to Mauricio Nunes Aleixo, the restaurant's night shift manager. "It's really classic for porteños, people from Buenos Aires," he said. "It's different for people from the other provinces; sometimes they don't even know what it is." (Fainá is also eaten with pizza in Uruguay, which is just across the River Plate from Buenos Aires and has close cultural ties to the city.)