Bring water to boil, add rice, cover and remove from heat; let sit until liquid is absorbed.
Mix together soup and milk from the soup can; stir until smooth. Add tuna, celery, onion, parsley and pepper.
Pour soup mixture over rice, mix to combine all ingredients. If mixture is too dry add a little more milk, you want it creamy but not soupy. Place mixture in casserole dish and bake 45-50 min. or until hot and bubbly, stir, add cheese to top of casserole and place back in oven until cheese is melted.