Submerge 1 1/4 cup beans in 3 cups water. Soak the beans for 8 hours.
Strain off excess water after 8 hours of soaking.
Pour the pre-soaked beans in a pan with 4 cups of water. Cover with a lid bring to a boil and cook on low for 2 hours.
After two hours remove from heat, and add 1 1/2 teaspoon salt, cumin and 2 tablespoon oil to the beans.
If you have a blender, pour the contents of the pan into the blender, and blend until smooth. Return the blended mixture to the pan, and cook on low without the lid until you reach the desired thickness. This process should take about 20-30 minutes.
The beans can be mashed by hand, run through a food mill, or a hand emulsifier to blend the beans if you don't want to mash by hand.
Cooking the additional 20-30 minutes will reduce the liquid, and infuse the cumin with the beans.
Serve warm. Store in a sealed container with a lid for up to a week.