Place the beans in a colander and sort through them to remove and discard any stones or debris. Rinse well.

Place the beans in a large pot and add the water, onion wedges, cumin, salt, oregano, and several grinds of pepper. Bring to a boil and skim off any foam that rises to the water’s surface, then reduce the heat to low and simmer for 1 hour. Check the beans. If they are not fully tender, continue simmering, checking them every 15 minutes, until tender, up to 90 minutes more. Add water to the pot as needed if it begins to dry out.

Place a fine mesh strainer over a large bowl. Drain the beans into the strainer, reserving the cooking liquid in the bowl.

Heat the avocado oil in a large skillet over medium heat. Add the diced onion and garlic and cook, stirring occasionally, for 5 minutes, or until soft and translucent. Stir in the beans and reduce the heat to low. Add ½ cup of the bean cooking liquid and use a potato masher to mash the beans until they reach your desired consistency, adding more cooking liquid, ½ cup at a time, as needed (I typically use 1 to 1½ cups). For smoother refried beans, blend the beans with an immersion blender or transfer to a food processor and process until smooth. Add the lime juice. Taste and add more salt and lime juice as desired. (I typically add another 1 teaspoon salt and ½ tablespoon lime juice at this point.)

Serve as a side dish or try one of the serving suggestions in the blog post above. Store leftover refried beans in an airtight container in the refrigerator for up to 5 days. They also freeze well.