Turn the heat under a 9-inch skillet to medium low and sprinkle 1/2 teaspoon of polenta flour into the pan. Immediately sprinkle the cheese over the polenta, distributing it evenly. Cook for 1 1/2 to 2 minutes, running the edge of a spatula under the perimeter of the wafer as the cheese melts and hardens to loosen it from the pan. Remove from heat and let it settle for 1 minute.
Using toaster tongs or a large tweezer and a spatula, lift the wafer from the skillet and turn over. Return to heat for 1 more minute.
Transfer the cheese wafer from the pan to a platter. If it breaks it doesn't matter because you must break it up anyway to eat it.
The wafer will keep crisp for a few hours, but taste best the moment it is done.