Of the many greetings with which a restaurant host can address his public — “Welcome,” “Hi there,” “Please, sit anywhere you like” all spring to mind — the phrase “Who sent you?” delivered in a husky voice at this quasi-private subterranean social club was new to us. If no one has, in fact, “sent you,” there aren’t any really good answers to this question, so we shrugged at an old photo of Joe Bastianich hanging on the wall, and mumbled, “He did.” Not that it really mattered. Istria Sport Club, established in 1959 as a home away from home for the neighborhood’s expat community from the Adriatic Coast peninsula (Bastianiches included), has long been accessible to curious interlopers. Our greeter, who also turned out to be our waiter, having concluded the niceties was happy to recommend the specialties of his birthplace: comforting homemade pastas like gnocchi and fusi, both in a succulent veal gravy; the Balkan sausages called cevapcici; and palacinke crêpes for dessert. Although rich and hearty, the food isn’t the main draw here. It’s the transporting atmosphere and the company, like Milano, an off-duty waiter from nearby Piccola Venezia, who recognized us and waved hello. “I’m here every night,” he said, as Zlatko, the affable club manager-cum-accordionist, pumped away on his squeeze-box, leading the dining room in a spirited sing-along.