Wellll - do you have a pressure cooker? I used my Instant Pot - 2 cups beans, 6 cups water, high pressure for 2 minutes, let drop pressure naturally; removed lid, strained off water, added 6 more cups water plus two big tablespoons bacon fat, a tablespoon chili powder, a tablespoon dried epazote, a big teaspoon dried oregano, another of cumin. Put back on high pressure for 10 minutes, let pressure drop naturally, opened and poured off some of the liquid, salted to taste and let stand til cool. Refrigerated, putting into a quart round container with some of the liquid - actually got two containers about 3/4 full each.
Tonight, I poured off a bit of the liquid then stuck an immersion blender in the container and blended til pretty smooth. Heated in the microwave. Next time I'll probably go ahead and put the blended beans in a skillet with another tablespoon of bacon fat or lard and fry them up til some of the liquid cooks off - they were just a tad bit thinner than I would have preferred - however, have had them served that way at many Mexican restaurants around here! I just like them a bit thicker.
Pretty easy overall, and these were some 4 year old pintos that we had vacuum-sealed in plastic containers but a couple of them lost vacuum - this was one of them. Had tried last week to cook the dang things in the roaster oven and after 12 hours they were nowhere near tender. KOTC declared them "dead" but I'm too stubborn to give up that easily, hence the pressure cooker, which worked like a charm. KOTC is now convinced it's THE way to cook beans and boy do I agree with him! Saved us from throwing out about ten pounds of dried beans.