Preheat oven to 350 degrees F.
Mix the three cans of soup with 2 cups of milk and the stick of butter in a saucepan. Place the saucepan over low heat as you work on the chicken, being sure to stir the soup mixture occasionally.
Remove any extra fat, skin, and gristle from the chicken and discard it. Cut the uncooked chicken breast meat into bite-sized chunks (or cubes).
When the soup mixture is hot and smooth, start assembling your casserole. Use a large oven proof (pyrex) casserole dish, about 14" x 10" x2". If you don't have a dish this large, make two small casseroles and cook for a shorter time. Spray baking dish with cooking spray, if desired. This is not a necessary step, however, though it might make serving a little easier.
Pour 1/2 of soup mixture into bottom of baking dish. Lightly and evenly sprinkle the long grain and wild rice over the top of the soup mixture. Reserve the seasoning pack for another use. Next, place the chunks of uncooked chicken evenly over the top of the rice. Now pour the remaining soup mixture over the top of the chicken chunks. Finish off the casserole by generously sprinkling the top with grated Parmesan cheese. You may grate fresh Parmesan cheese or use Kraft's. It is important that you sprinkle plenty of the Parmesan cheese. Betty uses 1/2 of the large Kraft can.
Cover the casserole with aluminum foil and bake in the preheated oven for about 1 hour. Remove the foil and brown the top for about 15 minutes. If you bake the casserole uncovered for 1 hour 15 minutes, it won't be quite as saucy. Serve while hot.