Cassareep

Cassareep is a thick black liquid made from cassava root, often with additional spices, which is used as a base for many sauces and especially in Guyanese pepperpot. Besides use as a flavoring and browning agent, it is commonly regarded as a food preservative although laboratory testing is inconclusive. Cassareep is made from the juice of the bitter cassava root, which is poisonous, as it contains acetone cyanohydrin, a compound which decomposes to the highly toxic hydrogen cyanide on contact with water. Hydrogen cyanide, traditionally called "prussic acid", is volatile and quickly dissipates when heated. Nevertheless, improperly cooked cassava has been blamed for a number of deaths. Indigenous peoples in Guyana reportedly made an antidote by steeping chili peppers in rum. To make cassareep, the juice is boiled until it is reduced by half in volume, to the consistency of molasses and flavored with spices—including cloves, cinnamon, salt, sugar, and cayenne pepper. Traditionally, cassareep was boiled in a soft pot, the actual "pepper pot", which would absorb the flavors and also impart them to foods such as rice and chicken cooked in it.

Source: Wikipedia