Vietnamese Shaking Beef with Bean Sprouts

Bo luc lac gets its name from the way cooks shake the wok so the beef cubes tumble and brown on every side. It came out of French-influenced kitchens in southern Vietnam, which explains the butter swirled in at the end. Dry the beef well and give it room: a crowded pan will stew the cubes gray. The bean sprouts take barely a minute and should still snap when you bite them, a clean contrast to the rich, peppery beef.