Bring the water (or water/milk mixture) and salt to the boil in a saucepan.
Gradually whisk in the polenta, stirring constantly to avoid lumps.
Reduce heat to low and cook, stirring regularly:~5 mins for quick polenta~20–30 mins for traditional medium polenta Stir in the butter and Parmesan. Taste and adjust seasoning.
Serve warm in shallow bowls as a creamy base for the coley and vegetables. Drizzle with a little olive oil before serving.