When ready to cook, drain the soaked beans and rinse them again under running water.
In a large pot, Mexican olla, or dutch oven, add the beans, water, garlic and onion. Bring to a boil over high heat, then reduce to a low simmer.
¼ medium white onion, 1 garlic clove, 6 cups water
Cover and cook on medium-low heat for 1 ½ hours. Add the salt, mix well and then taste and adjust the seasoning as needed.
½ teaspoon kosher or sea salt or more to taste
Cooked (covered) for another 30 minutes until the beans are tender and creamy but not falling apart, about 2 hours total.
If the liquid evaporates while cooking, add boiling water to maintain the same level of liquid.
To test when the beans are done, remove 2 or 3 beans from the pot and taste them or squeeze with a spoon. They will be done when the entire bean is tender.
Serve hot with rice, tortillas, or any other dish of your choice.