This blog has noted before that porridge, a hot dish consisting of boiled or stewed grains, with various flavorings added, shows up in many cultures. It was discovered early, and continues to be eaten today. The Romans and Carthaginians both had their own versions of it.
Last week, I discovered a web article indicating that the indigenous Americans (i.e., the peoples that were once called "American Indian") also made porridge, even though they did not have metal pots to heat it in. Instead, they heated rocks, and put the heated rocks in thick baskets, along with water and acorn flour--i.e., pounded acorns. The resulting hot food was called Wiiwish, or "acorn mush."
Many thanks to the Researching Food History--Cooking and Dining blog, for its illustrated article about acorn mush. The page on which the article about acorn mush appears includes a listing of virtual talks about early American food, both indigenous and otherwise.