A dehydrated potato product hailing from South America, particularly Bolivia and Peru. In the traditional method of producing chuño negro (black chuño), small, irregular potatoes are placed on a straw bed and left out overnight to freeze. After thawing the next day, the potatoes are gently stepped on to express moisture. This process is repeated, sometimes for weeks, until the potatoes are completely dry and look like small gray stones, at which point the skins are rubbed off. The white versionchuño blanco (also known as tunta )is made from larger, rounder potatoes and prepared in a similar way, except that after being frozen they're placed in water (tunta in running water and moraya in still water) for two or more weeks before undergoing dehydration. Chuño can be stored for years and must be soaked in water before being cooked. It will absorb the flavor of the liquid in which it's cooked. Both black and white chuño can be found in cans (sometimes brined) in Latin markets. Harina de chuño is white chuño ground into flour, which is sold in sacks.
From The Food Lover's Companion, Fourth edition by Sharon Tyler Herbst and Ron Herbst. Copyright © 2007, 2001, 1995, 1990 by Barron's Educational Series, Inc.