When it’s done in the U.S., cacio e pepe has the Goldilocks conundrum: Sometimes it’s too bland; sometimes it’s too clumpy; sometimes it’s just right. At longtime Larchmont staple Lusardi’s, the execution of this Roman pasta definitely falls into the “just right” category, with a smooth, emulsified sauce, chewy ropes of fresh pasta, and plenty of appropriately piquant pepper and pungent pecorino.