Step 1: Blend the Bean Sauce
In a blender, combine the pinto beans, onion, garlic, and about 1/2 cup of bean cooking liquid. Blend until completely smooth, adding more liquid as needed to reach a pourable, sauce-like consistency. Season with salt.
Step 2: Cook the Sauce
Heat oil in a skillet over medium heat. Pour in the blended bean sauce and cook, stirring often, for 5–7 minutes. The sauce should thicken slightly and lose any raw edge, but remain smooth and creamy. Keep warm.
Step 3: Warm the Tortillas
Heat a skillet with a light film of oil over medium-low heat. Warm each tortilla briefly on both sides until soft and pliable. Do not crisp.
Step 4: Assemble the Enfrijoladas
Dip each warm tortilla into the bean sauce, coating both sides. Place on a plate, add a small amount of cheese, and fold or roll.
Spoon additional bean sauce over the top and finish with your preferred toppings.
Serve immediately.