Simmer Dried Beans

1. Combine beans, water, onion, lard or shortening, and epazote in a heavy, 8-quart stock pot and bring to a boil over medium-high heat
2. Reduce heat to low, cover, and simmer for 1½ hours, or until beans are tender but not mushy. Remove onions and garlic. Add salt to taste

Make Refried Beans

1. Drain the cooked beans, reserving ¾ - 1 cup of cooking liquid. Mash beans with a potato masher or sturdy whisk (OK to leave some beans whole).In a large, heavy pot, melt the lard or oil over medium heat, add onion, and cook until onion is wilted and transparent, 5-6 minutes
2. Add mashed beans to the onion mixture and cook for about 5 minutes on medium heat, adding ¾ - 1 cup of the reserved cooking liquid from the beans if mixture seems too thick, stirring and mashing the beans against the side of the pot until beans have absorbed the oil and there are no traces of unblended fat. The end result should not be too stiff nor too runny; mashed potato-like consistency is what you're looking for
3. Transfer to a bowl and serve with sour cream and shredded Monterey Jack cheese

Note: Refried beans can also be made with canned beans, but you will need water, broth or stock for the liquid component of the dish.