In a large saucepan, bring 4 cups of water and 1 teaspoon of salt to a boil over medium-high heat.
Gradually whisk in the polenta, stirring constantly to prevent lumps from forming.
Reduce the heat to low and continue to cook, stirring frequently, for about 30 minutes, or until the polenta is thick and creamy.
Remove the saucepan from the heat and stir in the butter and grated Parmesan cheese until fully melted and combined.
Season with freshly ground black pepper to taste.
Serve immediately, garnished with chopped fresh parsley if desired.