Fifteen minutes after I sat down at BLT Prime, I popped the question: “What’s new?” I wanted to try dishes that were different from those offered at BLT Steak and BLT Fish, the other two restaurants in Laurent Tourondel’s fast-expanding BLT empire. My server couldn’t answer. I asked a second one. She didn’t have a clue either, but she asked a supervisor, who responded vaguely about “prime beef,” as if the $42 New York strip served at BLT Steak is just spiffed-up ground chuck. After dinner, I understood why my question had stumped the staff: There’s not much different about BLT Prime at all. Fans of the late Union Pacific will still recognize the bi-level space—some walls were removed so it’s much more open now, but otherwise it looks familiar. And fans of the first two BLTs (of which I am one) will recognize most of the dishes. Laurent Tourondel (the “LT” in BLT, “B” standing for bistro) has transferred almost the entire BLT Steak menu to BLT Prime: 9 of 9 BLT Steak appetizers, 14 of 14 entrées, 6 of 7 sauces, 15 of 16 side dishes. Then he simply added a few new ones to the list. On the plus side, BLT Steak is terrific, and to Tourondel’s credit, BLT Prime mimics the culinary execution, not just the menu. The winning BLT formula—pick protein, pick sauce, pick sides, bracket with light appetizer and heavy dessert—plays out with nary a flaw. From the tuna tartare, made with sweet, ripe avocado and a tart soy-lime marinade, to the signature foie gras BLT sandwich and kobe steak with a side of cheese-infused “creamy” spinach, the favorites taste just as good near Gramercy Park as they do near Central Park, if at the same murderous prices (median steak for one: $40). And in fairness, there are a few BLT Prime originals. Any time Tourondel touches fish he makes good with it, and his new lobster salad is no exception; it’s served with a cilantro-heavy gazpacho. The desserts at Prime are also originals (there’s a big emphasis on ice-cream sundaes). And, most notably, Tourondel has added to BLT Steak’s token veal, lamb and poultry choices at Prime, offering seven new options for those who are over beef. Like his steaks, the lamb is dry-aged, and the 14-ounce T-bone (served sliced in a skillet) would provide a perfect model for anyone opening a steakhouse in India. Nevertheless, this is not as new and different as the name suggests. Pretending that BLT Prime is anything but a big, downtown branch of BLT Steak is akin to a band adding a couple of songs to a greatest-hits CD and passing it off as a new album. Tourondel had two options: to go the way of chef-entrepreneurs like Mario Batali, Bobby Flay and fellow Frenchman Daniel Boulud and juggle multiple distinct, unique venues, or play it slightly safer and take the well-worn steakhouse path of the Mortons and Palms, serving essentially the same menu in a different location. Tourondel has leaned toward the latter, meaning that fewer new tastes have come out of his collective kitchen—making us, at least until his next venture, none the richer.