Egg and Lemon Soup with Toasted Orzo and Kale

I learned to make this velvety chicken soup spiked with lemon, called avgolemono in Greek, while I was an exchange student in the lovely port town of Kavala, in northern Greece. The soup is thickened with eggs and it can be tricky to make without the soup curdling, but my Greek host-mother taught me to add a bit of cornstarch to the eggs before tempering them with some of the soup to stabilize the mixture. The result is a thick, rich soup that’s nearly foolproof. You can substitute w