In a medium pot, cover pinto beans with filtered water. Stir in a pinch of baking soda, affix the lid, and soak for 8 hours or overnight.

Drain pinto beans and add fresh filtered water to cover. Add bay leaves.

Bring beans to a boil. Lower the heat and simmer uncovered for about an hour or until very soft. Add more water as needed during simmering to keep the beans covered.

Remove the pot from the heat and drain off all the bean cooking water into a bowl. Measure the amount of the cooking water with a glass measuring cup. It should be about 1-2 cups of liquid. After measuring, discard the bean cooking water.

Add warmed chicken stock in the same amount measured in the previous step to the pot of drained and cooked beans and mash it together with a potato masher or sturdy wooden spoon. Alternatively, blend it up in a food processor.

In a large skillet, heat the lard or bacon drippings over medium-high heat. Add the chopped onions and cook for 3-5 minutes while stirring frequently.

Add the minced garlic, chili powder, cumin, salt, cayenne, and optional jalapeno. Cook for one minute.

Add the beans and chicken stock mixture to the skillet, sprinkle in the oregano, and continue to stir and cook on medium-high heat. A thick paste will form after 5-10 minutes as the liquid is boiled off. If needed, add water in small amounts (1 tablespoon at a time) to keep the mixture from getting too dry.

Remove the refried beans from the heat and place in a serving bowl. Sprinkle on the grated cheese and serve immediately.

When cool, refrigerate leftovers in a glass bowl with a tight-fitting lid for up to four days.