i have made this before and frozen it...i've also made it with or without the rice...all ways equal the same thing..amazing! 
chicken & rice casserole 
what you need...
1  package sliced almonds 
2  boxes fast-cooking long-grain and wild rice mix 
1/4 cup butter 
4 celery ribs, chopped 
2 medium onions, chopped 
5 cups chopped cooked chicken 
2 cans cream of mushroom soup (99% fat free is best)
2 cans chopped water chestnuts, drained 
8oz container sour cream (fat free works!)
1 cup skim milk 
1/2 teaspoon salt 
1/2 teaspoon pepper 
4 cups shredded Cheddar cheese (2% reduced fat)
2 cups soft, fresh breadcrumbs 
what to do...
Preheat oven to 350°. Bake almonds in a single layer in a shallow pan 4 to 6 minutes or until toasted and fragrant, stirring halfway through.  Prepare rice mixes according to package directions. Meanwhile, melt butter in a large skillet over medium heat; add celery and onions. Sauté 10 minutes or until tender. Stir in chicken, next 6 ingredients, rice, and 3 cups cheese. 
Spoon mixture into a lightly greased 15- x 10-inch baking dish or 2 (11- x 7-inch) baking dishes. Top with breadcrumbs.Bake at 350° for 35 minutes. Sprinkle with remaining 1 cup cheese, and top with toasted almonds. Bake 5 minutes.