Chicken and Rice...leftover casserole... yummy

Greetings! I had chicken and rice leftovers and I said to myself, with the economy the way it is, I AM NOT throwing this out, though we were tired of eating it.  So I searched a little on the internet and came up with this casserole recipe. So, I made the chicken and rice leftover casserole.  I made it in the toaster oven and took it out to cool.  Before I could get a picture, my son ate most of it, going on about how good it was I couldn't possibly fuss at him for demolishing it before I could take a quick snapshot!  Here's the recipe...I hope you enjoy it as much as we did!

Yummy Chicken and Rice leftover casserole

1 package frozen spinach, thawed
2-3 Cups of leftover chicken and rice, mine has carrots and celery in it with chunks of white meat chicken
1/2 cup mozzarella- or more of any cheese, whatever you have on hand will do
1/4 cup panko bread crumbs or any crumbs you have on hand

Pan White Sauce:
   2 Tbsp Butter
   1/4 cup flour
   1 Cup milk - 2% or whole whatever works

Preheat oven to 350 degrees.  Begin by making the pan white sauce, put butter in small frying pan and melt, add the milk, add the flour and whisk until smooth and thickened 2-4 minutes.
Add the thawed package of spinach and the cheese and stir to combine
Add the leftover casserole, stir to combine

Pour into a small casserole dish, top with Panko or bread crumbs and bake for around 25-30 minutes.  Very good, so my son says!