Ingredients:

  Amount  Measure       Ingredient -- Preparation Method
--------  ------------  --------------------------------
   1      pound         dry beans
   1                    onion -- cut in four
   1                    onion -- chopped
                        salt
   8      cups          water
   8      leaves        epazote -- only if black beans
                        vegetable oil

Preparation:

Clean with water the dry beans. Put them in the 8 cups of water and let stand all night. In the morning you can cook them with the same water, 1 tablespoon of vegetable oil, onion, salt and epazote if the beans are black Let cook for 2 hours aprox. until done. Frijoles Refritos: fry the onion chopped with vegetable oil and then ground the beans, without onion used for first cook and epazote if you used them, and with the less broth you need (keep the broth for prepare a soup: " Fideo con caldo de frijol" Frijoles guisados: Fry the onion chopped with vegetable oil, when the onion will be transparent add the beans with all broth but without the epazote and onion used for first cook. The beans have to stay cooking for 1 hour aprox. Frijoles con Chorizo: fry the onion chopped with vegetable oil. Separately fry the "chorizo" when it will be cook add to the onion fried and then add the beans with broth. Cook for 1 hour aprox. There are many other ways for prepare the beans. It depends of the region in the country you can adorn the frijoles with "tortilla" cut in four, fried, and with fresh cheese.