Egypt is currently undergoing a severe economic crisis. One key reason is that it is importing much of the grain needed to feed its population (and livestock), and this has become expensive/difficult as a consequence of the Russian invasion of Ukraine.
On the other hand, during the times of the Roman Empire, Egypt was known as the "Breadbasket of the Mediterranean", and responsible for a significant fraction of the overall grain production of the entire Empire.
Besides some vague idea of desertification of North Africa being an important factor, how did this happen? When did Egypt move from net-exporter of grain to net-importer?
