In bowl, mash beans and their liquid with fork or spoon until majority of beans are broken; set aside.
Heat oil or lard in medium skillet over medium heat. Add onion and garlic. Cook, stirring occasionally, until vegetables are tender, about 5 minutes.
Add beans. Cook, stirring often, until bean liquid comes to a boil. Reduce heat and simmer until thick, about 5 minutes. Season with Adobo. Serve as a side dish with cheese sprinkled on top or use as a filling.