If you want to learn more about cocoa, see
this web page.
The cocoa tree is native to South America and was probably first cultivated by the Maya. Its scientific name, Theobroma cacao, means "food of the gods", and for Mesoamerican peoples it truly was: the seeds were made into a bitter, spiced drink reserved for important occasions, and the Aztecs even used them as currency. It reached Europe in the sixteenth century with the Spanish, and only much later became the sweet chocolate we know.
In my kitchen I use unsweetened cocoa powder, and raw cacao in no-bake desserts. But cocoa also works in savoury dishes: in fresh pasta dough, as in my cocoa tagliatelle, it gives a deep colour and a bitter note that pairs beautifully with vegetables and nuts.