The Zapotec name is pronounced roughly “gheenyádo shooba” and refers to two of the main ingredients, guiña (chile) and xuba (corn). The always helpful Venancia Toledo Hernández taught me this characteristic dish from the Isthmus of Tehuantepec. You must search for the right white field corn, a floury or “dent” type. Do not try to make it with flint corn or parched sweet corn, which don’t have enough starch.