Wash the beans and put in kettle.
Add the water (Unless beans are very old and hard, soaking is not necessary.)
Cook until tender but not mushy, for 2 hours or more; add the salt.
Melt the lard in a heavy pot (the Mexicans use a cazuela, a large earthenware pot with sloping sides and rounded bottom).
Then add the beans, a few at a time, mashing them with a spoon and adding a little of the bean liquid.
Continue until all the beans and liquid are used; then cook and stir until the mixture becomes thick.
Makes 6 servings.