Once all the flour has been poured into the pot, continue stirring until the mixture is homogeneous. Then lower the heat and keep on cooking, stirring occasionally so that the polenta does not stick to the bottom. The precooked polenta is ready after only 5 minutes, but it’s possible to cook it up to 10 or 15 minutes at most, if a more intense taste is desired. During the cooking, if the mixture is too thick, a little more boiling water can be added to make it softer.