In a large mixing bowl, combine the pre-cooked white cornmeal and salt.

Gradually add the warm water, stirring until the mixture forms a thick dough.

Add the mozzarella cheese, Parmesan cheese, and softened butter to the dough. Knead it with your hands until the ingredients are fully incorporated and the dough is smooth.

Divide the dough into 6 equal portions and shape each portion into a ball. Flatten each ball into a disc about 1/2-inch thick.

Heat a skillet or griddle over medium heat and lightly grease it with vegetable oil.

Place the arepas on the skillet and cook for 4-5 minutes on each side, or until golden brown and slightly crispy.

Serve warm, and enjoy the cheesy goodness!