Make the dough. Combine water, salt, sugar, and butter in a saucepan over medium heat. Bring to a boil before adding the cornmeal, mixing with a spatula to combine everything as the solids dissolve.
Add cheese. Once the mixture begins to solidify, remove from the heat and stir in cheese with a spoon.
Shape the sorullos. Once the dough has cooled enough to touch, scoop one tablespoon at a time and roll into a log with your hands. Continue until all the dough has been shaped.
Fry until golden brown. Heat the oil to about 350 degrees F / 177 degrees C. Carefully fry the sorullos in batches, making sure to not overcrowd the pan.
Drain on a paper towel plate before enjoying with mayoketchup!