01 -
Set oven temperature to 350°F (175°C).
02 -
In a greased 9x13 inch baking dish, combine the uncooked orzo and warm chicken broth. Let sit for 30 minutes to allow the orzo to soften.
03 -
Add the cooked chicken to the softened orzo and broth mixture, stirring gently to combine evenly.
04 -
In a separate bowl, whisk together cream of chicken soup, sour cream, lemon juice, lemon zest, garlic powder, onion powder, black pepper, celery salt, dried parsley, and grated Parmesan cheese until smooth.
05 -
Pour the prepared sauce over the orzo and chicken mixture and fold gently to integrate all ingredients.
06 -
Sprinkle half of the grated Swiss cheese evenly over the casserole surface, then cover tightly with aluminum foil.
07 -
Bake in the preheated oven for 35 minutes.
08 -
Remove foil carefully, stir gently, then continue baking uncovered for an additional 25 to 30 minutes until the orzo is tender.
09 -
Raise the oven temperature to 375°F (190°C).
10 -
Sprinkle the remaining Swiss cheese over the top and bake for 15 to 20 minutes until melted and lightly browned.
11 -
For a deeper golden crust, broil the casserole for 1 to 2 minutes, watching carefully to prevent burning.
12 -
Allow the casserole to rest for 15 minutes after baking to thicken and set before serving.