Bring the water to a boil in a large, heavy pot. Add the salt. Gradually whisk in the cornmeal. Reduce the heat to low and cook, stirring often, until the mixture thickens and the cornmeal is tender, 15 to 20 minutes. Remove the pot from the heat. Add the cheese, milk, butter, and parsley. Stir until the butter and cheese have melted. Season with salt and pepper, to taste. Transfer the polenta to a bowl and serve.