The cassava root vegetable contains cyanide and must be processed before it can be eaten. First it is peeled, then ground or grated. Then the mush is put into a woven 'sock' called a matapi. The matapi is hung up and pressure applied by someone sitting on a branch which passes through the bottom loop of the matepi. This squeezes all the water, and the cyanide, out of the cassava. It can then be shaped and fried in an enormous pan to make cassava bread or farine. Made well it's actually very good!