My wife is from Honduras, so we eat frijoles refritos almost daily! We use Central American red beans that are popular in El Salvador and parts of Honduras, they are usually found in any Mexican Grocery labeled as "Central American Red Beans". I think they taste best when cooked in a soup pot, so we have a big pot we use. I usually do 2 pounds at a time. We don't presoak, just rinse/clean. I add 3 cloves of garlic and about 1/4 of a red or white onion sliced from side to side (through the middle) so that the onion remains in rings. I then cook for 2-4 hours on medium heat depending on how fresh/dry the beans are. When we get them straight from Honduras they only take 2 hours, but some of the store bought ones take much longer. When beans begin splitting or breaking apart they are ready, I then add at least 3 teaspoons of salt and stir for a minute or two and then turn off the heat. When beans are cool I add a thin layer of oil to the bottom of a separate pan. While the oil is heating I transfer some of the beans (with the pieces of garlic and onion) to a blender and I make sure the bean broth only comes up to about 3/4 of the amount of beans (hope that makes sense?) I then blend until well liquified. I then pour the bean mixture into the pan with the oil.....careful oil may splatter a bit, and mix, at the same time I turn the heat down to medium low. I let cook and stir occasionally until oil is well incorporated into beans, and the beans appear frothy.....and then we are done....simple but good! Might not be Tex-Mex style, but better than it may sound. I usually save some of the cooked beans for making other dishes too, that is why i make such a big pot.