Screw authenticity,” said the man in the Borsalino hat perched on the stool next to the Underground Gourmet at Salvation Taco, a new bar and taquería off the lobby of a Murray Hill budget hotel. “This is delicious.” Señor Borsalino, like the U.G. and practically everyone else, was eating something called “Moroccan lamb on naan,” even though it was listed under the menu heading “Tacos.” The so-called taco in question was about the size and shape of a bar of Dove soap and more like a cross between a miniature gyro and a bruschetta. Eating it was tricky: When you tried to pick the thing up or fold it in half taco style (which, by the way, doesn’t work), cubes of juicy meat and diced cucumber spilled out onto your lap and hot lamb grease shot down your sleeve. And yet, like the man in the hat said: delicious.