Also known in indigenous languages as Ommaï (Uitoto), Kígai (Muinane), Do-Hmepa (Bora), Ualako (Yucuna)Ají negro (Black chilli) is a sauce obtained from the juice of bitter manioc (Manihot esculenta) with the addition of hot chilli peppers. It is traditionally produced by the indigenous people of North West Amazonia as a basis for a variety of recipes or more plainly as a dip for cassava bread. The preparation of black chilli involves a complex process of filtering and cooking to get rid of cyanide contained in raw manioc. Different manioc varieties are grown in slash-and-burn polyculture gardens known as chagras. After harvesting, manioc tubers are peeled, washed, chopped and soaked for one or two days in stream water. Chunks are then mashed with a heavy wooden pounder in a large mortar obtained from a hollow tree trunk (balac). The pulp is placed inside a long woven strip (matafrío) that is wrapped, hung and twisted for several hours to extract the starchy juice from the pulp. The flour thus obtained is either roasted or used to make cassave bread, while the juice is left to rest for several hours to separate the starch, later used to make starch cassave and cahuana, a thick beverage with added fruit juice. The filtered juice (without the starch) is simmered for five to eight hours until it thickens. Different kinds of hot peppers are added to the sauce. Depending on the recipe for which it will be used other ingredients may be added, such as fish, meat, ants (Atta and other unspecified species), vegetables, flowers (such as those of the Bactris gasipaes palm) and oily seeds (of Mocambo, Theobroma bicolour). Black chilli can also be made by grating and sieving fresh manioc, without macerating it in water, to obtain a sauce with a sweeter taste and a lighter colour. Variations in taste, colour, and thickness mirror ethnic differences, and women proudly distinguish their own black chilli sauce from that of other ethnic groups. While the ingredients used to make black chilli are not endangered, the knowledge related to its preparation and consumption is. Perhaps due to the long preparation process but mostly to cultural assimilation, the making of black chilli is uncommon among younger women. Regardless of its cultural significance and great gastronomic potential, this recipe may get lost in the span of a generation. Black chilli is traditionally used by indigenous people of North West Amazonia such as the Uitoto, Bora, Muinane, Ocaina, Andoke, Nonuya, and Yucuna ethnic groups. It is eaten daily with cassave bread, and on festive occasions it is prepared with the addition of other ingredients to obtain a variety of dishes that identify the local ethnic gastronomies. The process of filtering, squeezing, thickening and mixing to transform toxic substances into life sustaining food have a central place in Amazonian thinking. It appears in myths, and is used as a metaphor to explain the making of human beings, theoretical and practical knowledge, and shamanic healing practices that restores good health and the social-environmental balance.