NATIVE AMERICAN FOODS
'(<a href="http://www.j-archive.com/media/2011-11-28_DJ_01.wmv">Kelly of the Clue Crew presents the clue from the National Museum of the American Indian in Washington, D.C.</a>)  Raw acorns can be poisonous but Native Americans found that, once cracked & cleaned, they could use the ground-up meal in breads and in soups for this purpose, like cornstarch'
a thickener