Cassava by John Spottiswood.

People in Hispanic countries use cassavas much like Americans use potatoes. There's both a sweet and a bitter variety of cassava. The sweet one can be eaten raw, but the bitter one requires cooking to destroy the harmful prussic acid it contains. It's often best to buy frozen cassava, since the fresh kind is hard to peel. Look for it in Hispanic markets. It doesn't store well, so use it within a day or two of purchase.