Step 1Heat oven to 350 degrees. In a 3- to 4-quart oven-proof pot, combine the water, salt, polenta and butter. Bake, uncovered, for 1 hour and 20 minutes. Stir polenta and bake for 10 more minutes. Remove the pot from the oven and stir in the grated cheese. Set aside 5 minutes to rest before serving.
Step 2To serve, spoon the polenta into each of 6 warmed shallow pasta bowls. Serve immediately.