Creamy Chicken and Rice Soup

cooked wild rice blend (I used two boxes of "Uncle Ben's Long Grain and Wild Rice" and threw away the seasoning packets)

chicken breasts

onion, peeled and diced

carrots, peeled and diced

stalks of celery, diced

garlic, minced

plus 3 tablespoons) butter

plus 3 tablespoons) flour

whole milk (you can use 2% to lighten it up if you want)

chicken stock