Wikipedia says:
"Irvingia is a genus of African and Southeast Asian trees in the
family Irvingiaceae, sometimes known by the common names wild
mango, African mango, or bush mango. They bear edible mango-like
fruits, and are especially valued for their fat- and protein-rich
nuts.
The subtly aromatic nuts are typically dried in the sun for
preservation, and are sold whole or in powder form. They may be
ground to a paste known variously as dika bread or Gabon chocolate.
Their high content of mucilage enables them to be used as
thickening agents for dishes such as ogbono soup. The nuts may also
be pressed for vegetable oil."