These beans are better made a day ahead of time and reheated. In Oaxaca, it is common to serve these beans in small earthenware dishes. The cook sometimes places a chunk of soft white cheese in the bottom of the dish before adding beans. You can also cook these beans in a slow cooker on the low setting.

1 pound black beans
1 large onion, chopped
1 bay leaf, crumbled
3 tablespoons olive oil
Salt, to taste
Fresh epazote leaves, finely cut

Cover black beans with water and soak overnight.

Pour off water. Cover with more water and bring to a boil. Discard this water. Cover beans with water again and bring to a boil. Reduce heat until the beans are barely simmering and cook until they are soft, anywhere from 1 1/2 to 4 or 5 hours, depending on the beans. Keep stirring frequently to make sure the beans don't burn.

When the beans start to become soft, add the chopped onion, bay leaf and olive oil. Thirty minutes or so before you think the beans will be done, add salt and epazote leaves.