In every polenta recipe I have ever seen, the authors insist that the polenta has to be stirred over low heat for half an hour or so before it is thoroughly cooked. When I worked in an Italian restaurant, I would follow this process (commonly making many portions at a time).
However, when making it at home in small portions, I find it tastes just the same if it is whisked over low heat for just enough time for the grain to absorb the liquid.
Why the insistence on cooking small portions (4?) for half an hour?
Please note that I am talking about normal fine grain polenta here, not some sort of 'quick' polenta.