Rinse and sort dried pinto beans
Soak beans overnight or use a quick-soak method
Drain and rinse the soaked beans
Place beans in a pot and cover with fresh water
Add onion, garlic, and salt if desired
Bring to a boil, then reduce to a simmer
Cook until beans are very tender
Drain the beans, reserving some cooking liquid
Heat lard, oil, or butter in a skillet
Add chopped onion or garlic if desired
Add the cooked beans to the skillet
Mash the beans with a potato masher or spoon
Stir in reserved liquid until desired consistency is reached
Season with salt, pepper, cumin, or chili powder
Cook and stir until thick and creamy
Serve warm