Most focaccia bread is so heavy and greasy, its olive oil soaks through the paper it's wrapped in. The focaccia baked at Liguria, a bare-bones storefront across the street from Washington Square, is soft, slightly spongy, and absolutely greaseless -- a light and lovely snack. The bakery's mastery of this centuries-old Italian hearth bread derives from a certain singularity of purpose: Aside from the occasional Easter panettone, focaccia is the only thing produced on the premises. There are five varieties: plain, garlic, onion, raisin, and "pizza," which is gilded with scallions and a mild tomato sauce. A $3 slab is about 5 by 10 inches and half an inch thick, and if you want to snack on it while you stroll the neighborhood they'll cut it into rectangles and wrap it in butcher paper for easy scarfing.