Active time: 10 min Start to finish: 2 hr
Cooks' notes:
• If you don't have time to cook dried beans, rinse and drain a 19-ounce can of cooked black beans. Cook onion in oil in a small heavy skillet over moderately low heat, stirring, until softened, then stir in beans, cilantro, salt, and 1/4 cup water and simmer, stirring, until beans are heated through. • Beans can be cooked 1 day ahead and cooled, uncovered, then chilled, covered. Reheat before serving.