Preheat the oven to 400*. With a pastry brush coat the bottom and sides of an 81/2-or 9-inch square shallow baking dish with 1 Tblsp. of the soft butter, then scatter 1 Tblsp. of flour or grated parmesan over the bottom of the dish.
Tip the dish from side to side to spread the flour or cheese evenly on the buttered surfaces and set the dish aside.
Place the corn in the jar of an electric blender and blend at high speed until it becomes a smooth puree.
In a large bowl, combine the pureed corn, cornmeal, milk, 1/4 cup olive oil, grated munster cheese and salt, and mix thoroughly.
In a heavy 8- to 10-inch skillet, heat the remaining tablespoon of oil over moderate heat. Add the onions and cook, stirring frequently, for 4 or 5 minutes, or until they are soft and transparent but not brown.
With a rubber spatula, scrape the onions into the corn and cornmeal mixture. Beat the egg whites with a whisk or an electric mixer until they are firm enough to form unwavering peaks on the beater when it is lifted out of the bowl.
Beat the yolks in a separate bowl until they are thick and lemon colored, then fold them into the egg whites. Gently but thoroughly fold the combined eggs into the corn mixture, then pour it into the prepared baking dish.
Dot the top with the remaing 1 Tblsp. of the butter. Bake in the middle of the oven for 45 minutes.