The only glatt kosher lounge in New York, Talia's cultivates a nostalgic bar mitzvah mood with American "finger food," Lisa Loeb on the turntables (at low volume), and giggly clumps of sober, appropriately dressed girls. As Israeli-born owner Ephraim Nagar puts it, "No one is really losing their mind here." An upscale steak house on the weekdays, the restaurant transforms itself into a post-Shabbat party every Saturday night with a certified supervisor on site to make sure that all food, drinks, and utensils are blessed; when he leaves, he locks the refrigerator, sealing the edges with duct tape. According to regulation, the dimly lit loungerecently dubbed "Club 613" (other name candidates included "Ole Moses," "Bar Mitzvah," and "Rockin Rabbi")forbids dancing. If people become overwhelmed by the combo of their $9 martinis and the steady procession of '80s hits (and they do), they're politely asked to sit down. Meanwhile, Nagar and other wandering bartenders take a cooing interest in the flirtations of their guests, ushering yarmulked men toward unaccompanied women. "There are great possibilities for matchmaking because everyone has similar beliefs and traditions," says Nagar, gazing proudly around the room. "Who needs to assimilate?"