Rinse barley under cold running water until water is clear. In medium saucepan bring broth or water to a boil. Stir in barley. Cook, covered, over low heat, until water is absorbed, and barley is tender, 35-45 minutes. Do not remove lid or stir while barley is cooking. Let stand, covered, for 5 minutes. Meanwhile heat the oil in a small skillet until hot enough to sizzle a piece of onion. Add the onion and cook, stirring, until onion is golden, 10 minutes. Add onion and oil to cooked barley and stir.