Cut or tear the ancho chiles into 2-inch-or-so pieces, discarding the seeds and stems.
Place in a dry skillet over medium heat and toast for about 5 minutes, turning them occasionally, just until fragrant, without allowing them to char.
Transfer to a blender, add 5 cups of hot water, and blend until smooth.
Heat the oil in a stove-top or electric pressure cooker or Dutch oven, uncovered, over medium heat until it shimmers.
Add the onion and garlic and cook, stirring frequently, until the onion turns translucent, about 5 minutes.
Add the salt, pepper, oregano, cumin, and paprika and cook, stirring, until very fragrant, about 1 minute.
Stir in the beans, along with the ancho mixture, plus more water as needed to cover the beans by 1 inch. If you’re using a pressure cooker, lock on the lid and bring the cooker up to high pressure. Cook for 45 minutes if using a stove-top model or 55 minutes for electric. Let the pressure naturally release, then open. If you’re using a Dutch oven, cover and cook over low heat until the beans are very tender, up to 4 or 5 hours, stirring occasionally and adding water if the beans seem dry on top.
Use a masher to lightly mash some of the beans in the pot, leaving some whole. Stir in more water to loosen, if necessary, and add more salt and pepper to taste.
Serve warm, with the accompaniments of your choice.