For the first time since expelling its Jews in the 15th century, Portugal has once again begun producing kosher olive oil under strict rabbinical supervision. The product, which is being marketed under the name Ribeiro Sanches Kosher, is manufactured by Penazeites, one of the country’s most important manufacturers of olive oil, in the central Portuguese town of Penamacor. The oil bears a “triangle-K” kosher symbol and is under the supervision of Rabbi Elisha Salas, an emissary of the Jerusalem-based Shavei Israel organization (www.shavei.org),who serves as rabbi of the Jewish community of Oporto, Portugal’s second-largest city. The olive oil is also...