Polenta is simply cooked cornmeal.
Expensive Italian restaurants have created quite a mystique about polenta. Years ago, you never saw polenta on a restaurant menu. Now no self-respecting chic Italian restaurant doesn't have at least two fancy polenta dishes, while the less fashionable "Luigi's" wouldn't even think of offering it.
Polenta, you see, has a very humble origin and history--it's an ancient, peasant dish from Northern Italy. The affluent rarely touched it. You may have heard Italian cooks boast that it was a main diet of Roman soldiers on military campaigns. Well, early Romans may have eaten a mush (a thick porridge) called polenta, but it certainly couldn't have been made from corn, which was unknown in Europe until the 16th century.
Grain, which was grown for animals, is indigestible by humans unless it is first ground into meal or flour. (The word "meal" originally meant ground grain.) Cereal or flour is easily transported and stored, and can later be mixed with water and baked, grilled, or cooked. The first polenta was cooked buckwheat meal, or mush. It wasn't highly nutritious or tasty, but it prevented famine. The Romans in the British Isles may have given the Celts the idea for Haggis.
Italians, the world's greatest cooks, figured out ways to make polenta rich, flavorful, and nutritious, by serving it with other less austere foods, and enriching it with dairy products, such as butter and cheese. They have also made its preparation a family ritual, including the use of the copper paiolo and wooden spoon. And the use of cornmeal in place of ground buckwheat added variety. Today all Italians, not just the poor, enjoy polenta, even though it is still associated with hardship and deprivation, as it literally kept millions alive.
In Italy and the rest of Europe, corn is still primarily grown for animal feed. It's interesting that aside from polenta, you won't find many uses for corn or its byproducts in Italian cooking.
You can buy corn flour imported from Italy called polenta, but you can also find perfectly good domestic cornmeal in the U.S. and other corn-producing countries. The more coarsely ground cornmeal is preferred over the more finely ground flour, as it gives a more robust texture.
Once prepared, polenta doen't have to be consumed immediately. It can be chilled and cut into shapes for grilling, baking, roasting, or frying. Look around--you will find limitless uses for polenta!