Rinse the beans in water and remove any small stones, pieces of dirt, or bad beans.

Cook the beans in water using either the regular method (simmer covered for 2.5 hours) or the pressure cooker method (cook for 30-35 minutes until beans are soft and skins are barely breaking open).

Strain the beans from the cooking water.

Add the onions (if using) and lard/fat/oil to a wide, sturdy frying pan on medium-high heat. Cook onions until translucent.

Add the strained beans and about 0.25 cup of water to the pan. Using a potato masher, mash the beans in the pan while cooking them until they are a rough purée.

Add more water if necessary to keep the fried beans from getting too dried out. Add salt to taste.

Add a few slices of cheddar cheese or 0.5 cup grated cheddar cheese if desired.

When beans are heated through (and optional cheese melted), the beans are ready to serve.