Preparation Bring black beans, onion, oil, water (8 cups), and 1/2 teaspoon salt to a boil in a 6- to 8-quart heavy pot, then reduce heat and simmer, covered, until beans are tender, 1 1/2 to 2 hours (depending on age of beans). Thin to desired consistency with additional water. Stir in Sherry and remaining teaspoon salt, then soy sauce and vinegar to taste (start with 1 tablespoon each), and simmer, uncovered, stirring occasionally, 5 minutes. Cooks' notes:·Beans can be cooked in about one third of the time in a 6- to 8-quart pressure cooker. Follow recipe, combining beans with onion, oil, water, and salt in pressure cooker. Seal pressure cooker with lid and cook at high pressure, according to manufacturer's instructions, until beans are tender, 30 to 45 minutes. Put pressure cooker in sink (do not remove lid) and run cold water over lid until pressure goes down completely. ·Beans improve in flavor if cooked at least 8 hours ahead. Chill, uncovered until completely cooled, then covered up to 1 week, or freeze up to 3 months. Beans thicken considerably as they stand, so thin with water when reheating over moderately low heat.
Preparation Bring black beans, onion, oil, water (8 cups), and 1/2 teaspoon salt to a boil in a 6- to 8-quart heavy pot, then reduce heat and simmer, covered, until beans are tender, 1 1/2 to 2 hours (depending on age of beans). Thin to desired consistency with additional water. Stir in Sherry and remaining teaspoon salt, then soy sauce and vinegar to taste (start with 1 tablespoon each), and simmer, uncovered, stirring occasionally, 5 minutes. Cooks' notes:·Beans can be cooked in about one third of the time in a 6- to 8-quart pressure cooker. Follow recipe, combining beans with onion, oil, water, and salt in pressure cooker. Seal pressure cooker with lid and cook at high pressure, according to manufacturer's instructions, until beans are tender, 30 to 45 minutes. Put pressure cooker in sink (do not remove lid) and run cold water over lid until pressure goes down completely. ·Beans improve in flavor if cooked at least 8 hours ahead. Chill, uncovered until completely cooled, then covered up to 1 week, or freeze up to 3 months. Beans thicken considerably as they stand, so thin with water when reheating over moderately low heat.