This is an ancient dish, that predates bread. Also known variously as pottage, mush, polenta, and so forth. Soon after it was discovered that the seeds from certain plants (wild wheat, millet, barley, and so forth) were edible, it was discovered that they were even more edible if boiled (and perhaps banged up a bit beforehand) in a clay pot. Rather more rough around the edges than your modern hot breakfast cereal, but at the time considered quite tasty and nutritous. Low cost and accessability have made this dish so popular that it is still eaten by millions world wide as a dietary staple (at least until something better can be found). Medieval porridge was often mixed with beans, vegetables, and spices. While baking, and bread, is the preferred method of consuming grain, one must first create flour. This is a very time consuming task. Moreover, grain will keep for several years if stored properly while flour goes bad much faster. Pottage could also be prepared as a delicacy, when cooked in milk, with spices and sweets like honey or fruit added, the dish became frummery, a delicacy enjoyed by all who could get it.