Persian Layered Chicken and Rice Casserole

"This is a delicious family-friendly casserole of saffron rice that is layered with chicken and onions. A rice, egg, and yogurt layer forms a firm crust at the bottom of the casserole. When you flip it onto a platter and lift the casserole dish off, you will see the beautiful browned crust on top, with the juicy chicken, onions, and steamed rice layers beneath it. There's also a tasty yogurt sauce to serve alongside!"