In a large saucepan, bring the water or milk (or a combination of both) to a boil. Add the salt.
Gradually add the polenta to the boiling liquid, whisking constantly to prevent lumps from forming.
Reduce the heat to low and continue to cook the polenta, stirring frequently, for about 30-40 minutes. The polenta should become thick and creamy.
Stir in the butter until melted and well combined.
If desired, add the grated Parmesan cheese and stir until fully incorporated.
Transfer the polenta to a serving dish and garnish with fresh herbs if desired.
Enjoy your meal!