Set aside a cup of the yucca water and drain the excess. Mash the yucca and garlic with a potato masher or mash with a fork. Return to the pot, add 1/2 cup of the water you set aside and butter. Stir everything while the pot is on low heat. Add the cheese and use a wooden spoon to mix it in. Add more salt, if needed. You can also add a little more water if needed.