Club Chicken Casserole

1/2 cup butter
1/3 cup celery, chopped
1/4 cup all-purpose flour
1/2 cup onions, diced
3/4 cup evaporated milk
1/2 cup water
1 cup chicken broth
1 can cream of mushroom soup
2 1/2 cups chopped cooked chicken
3 cups cooked rice
1 teaspoon salt

Melt butter and add flour, celery and onions. Brown slowly for 2 minutes, then add milk, water, chicken broth and soup: stir until thick. Remove from heat and add remaining ingredients. Stir lightly until well mixed. Pour in pan and bake at 350 degrees F for 40 minutes.