Bring lightly salted water to a boil. After measuring out proper amount of polenta for the recipe, pour into boiling water slowly in a steady stream while stirring. Turn heat down to low and continue to stir slowly. Polenta really needs to be stirred continuously while cooking. This will keep it from getting lumpy. Unless the recipe specifically calls for it to be served creamy continue to cook about 15 minutes, stirring until it thickens almost to the point a small wooden spoon can stand up in it. Pour immediately into a pan to allow it to set up to the firmness that allows you to cut into serving pieces.