From Simply Mexican by Lourdes Castro
1 pound dried black beans
8 cups water
1/2 cup olive oil
1 onion, chopped
4 cloves garlic, finely chopped
4 tsp salt, plus more as needed
1 tsp black pepper
1/2 tsp dried oregano
1 bay leaf
1. Rinse the dried beans with water and pick through them, removing any pebbles or debris you may find. Combine the beans and water in a large saucepan, cover with a lid, and allow to sit at room temperature for 8 hours, or overnight.
2. Place the saucepan with the soaked beans and water over medium heat. Simmer the beans, uncovered, for 1 hour or until tender.
3. Test one bean by pinching it between your fingers. If it easily caves to pressure, the beans are ready. If not, continue cooking until softened.
4. Once the beans are tender, saute the onion and garlic. Heat the olive oil in a skillet over medium-low heat. Add the onion and garlic and cook them slowly over low heat, for about 10 minutes. You want to sweat the vegetables -- not brown them. When ready they will be very soft and translucent.
5. To the simmering beans, add the onion mixture along with the salt, pepper, oregano, and bay leaf. Mix well and simmer, uncovered, for another 45 minutes. At this point, the liquid in the pan should be barely skimming the top layer of beans.
6. Before serving, check for seasoning and add salt and pepper as needed.
Can freeze these beans after cooking for up to 2 months, just remember to freeze in small enough portions that you grab only what you need.