Sweet Onion-Lemon Butter Canapés

Dark bread is slathered with lemon-honey butter, chilled, topped with slim onion slices and dill, cut into narrow rectangles, sparked with crisp coarse salt and pepper, and passed as a special hors d’oeuvre— one that demands iced vodka or aquavit. Rich imported butters, usually from France or Denmark, are well worth the extra cost for their satiny texture and deep flavor. Choose a dense, grainy, dark bakery loaf (pumpernickel, 7-grain, or similar) that can be sliced thin.