Why are beans so prevalent in Mexican cooking? Well, as we know, corn is the basis of most foods here. And, as any vegetarian can tell you, beans and corn combine to make a complete protein!
Mexican-Style Beans can be served as a side dish, or in place of potatoes or rice. They are also wonderful refried to use as a side dish, in enchiladas, burritos, or tamales, or as an appetizer with tortilla chips.

Mexican-Style Beans
To make 6 to 8 servings:
1 pound beans (red, pink, pinto, or black)
6 cups cold water
1 small onion, halved
3 tablespoons lard or vegetable shortening
2 teaspoons salt
1 tablespoon finely chopped onion

Wash and rinse the beans, picking out any little stones or discolored beans. Let soak overnight, refrigerated, in 6 cups water. In a large bowl Drain. Put in a large pot with t6 cups water and the halved onion. Bring to a boil over medium heat, cover, and reduce to a simmer. Hen the beans begin to wrinkle, add 1 tablespoon of the lard or vegetable shortening.. When the beans are almost completely tender, add the salt. If you add the salt at the beginning, the beans will remain tough. Continue cooking until the beans are very tender, a total of about 2 hours. (This can also be done in a pressure cooker.)
Heat the remaining 2 tablespoons of lard in a skillet and sauté the chopped onion, until translucent. Add to the beans, and simmer until slightly thickened.

And here are two variations on Mexican-style beans:

Refried Beans
To make 6 servings:
1/ 2 cup lard or vegetable shortening
3 cups of cooked beans, (red, pink, pinto, or black)
Bean broth
In a skillet, heat the lard or vegetable shortening over high heat. Add the beans in small amounts, along with some of the broth, mashing them with a fork or potato masher. They should form a coarse paste. Reduce heat and continue cooking until the beans begin to form a solid mass. You should be able to roll the refried beans around in the skillet like an omelet. Serve hot as a side dish, or use in an appetizer such as tostadas, or as a filling for burritos, enchiladas, or tamales.
Refried beans may be served with a selection of grated mild, white cheese, such as Monterey jack, friend and crumbled chorizo sausage, sliced avocado, and - of course - your salsa of choice.

Frontier Beans
To make 6 to 8 servings:
8 slices bacon
2 chiles poblanos, roasted, peeled, seeded, and deveined
1 pound Roma tomatoes, roasted, peeled, seeded, and chopped
1 recipe Mexican-style beans
2 chorizo sausages, removed from their skins and crumbled
In a large skillet, brown the bacon, then remove and drain. In the remaining bacon fat, fry the chorizo sausage meat, chilies and tomatoes about 5 minutes, until the sausage is browned. Add the beans and the bean broth. Simmer, stirring occasionally, until slightly thickened.