In Japan, hurried commuters grab bento-box lunches at train stations. Here in the United States, speedy multicourse lunchessome inspired by the bentoare making their way into the most elegant restaurants. At the Topaz Bar in Washington, D.C., chef Stafford Mather's bento holds steamed rice, pickled vegetables, salad and an entrée, like seared scallops with gingered grits. Chef Christian Delouvrier of Manhattan's four-star Lespinasse recently introduced "Le Quicker," a bento-style compartmentalized platter; items have included foie grastopped chestnut soup, oven-roasted tomatoes, rouget with potato confit and a pear tart. For customers who can't spare the time to sit, chef Jason Paskewitz of Wave in Chicago packs vintage silver lunchboxes with a sandwich, chips, bottled water and, for dessert, a homemade "ding dong"chocolate cake wrapped in ganache with a cream center.