By Orge Castellano MADRID (JTA) — The typical menu at Xerta, a Barcelona restaurant that earned a coveted star from the Michelin Guide, reads like a haute-cuisine treyf banquet: non-kosher dishes such as lobster, squid and oysters. Yet the restaurant has become a hotspot for Barcelona’s small number of kosher-keeping Jews. That’s because with a little advance notice, Xerta will prepare food according to Jewish dietary laws in a separate kitchen, under the supervision of a local Chabad-Lubavitch rabbi. The restaurant pursued kosher certification, which makes Xerta the only Michelin-starred kosher restaurant in the world, largely to attract Barcelona’s rising...