This haunt of chefs and culinary students is hidden from the casual shopper, but many dedicated amateur home cooks know it and are made welcome. And though the showroom is small and utilitarian, its shelves brim with inventiveness and beauty. Visitors bend like acolytes over the knives, marshaled to order in glassed-in cases. J. B. Prince was an early importer of those handmade by Misono, one of Japan's great sword manufacturers; among the selection, there's one to fit every hand and skill level. Along one wall are Mauviel and Sitram saucepans in a startling variety of sizes. The rows of gleaming cake pans and tart molds may well persuade a nonbaker to conquer a fear of flour. Don't expect the cozy clutter of small kitchen appliances and tabletop accouterments you'd find in a typical cookware shop. J. B. Prince is a restaurant supplier, and the choices are strongly influenced by its clientele.