Rinse pinto beans in a colander and remove any unwanted pebbles.
Place beans in a large Dutch oven and add diced onion, bay leaf and 1 teaspoon salt. Add water to cover approximately 2 inches.
Bring water to a boil, then cover and reduce heat to a simmer. Simmer for approximately 1 1/2 hours or until beans are tender. Drain beans, reserving the bean broth water.
Return Dutch oven to the stove and melt lard over medium heat. Add the garlic and jalapeño and sauté for 1 minute.
Return beans to the pot and add cumin, oregano and 1 teaspoon salt. Cook an additional 1 to 2 minutes, stirring frequently.
Add 3/4 cup bean broth and continue to stir the beans. If you like your beans chunky, you can use a potato masher or if you like them more smooth, use an immersion blender. Additional bean broth can be added to achieve the desired consistency.
Taste and add additional salt if necessary.
If serving as a side dish, garnish with a little chopped cilantro, some cotija cheese or melted cheddar and/or jack cheese.
Notes
Soaking beans overnight is not necessary for this recipe, but if you want your beans to cook faster, place them in a large Dutch oven overnight with water to cover approximately 2 inches. When ready to cook, drain and rinse the beans and proceed as directed above.