Place cooked potatoes in a large mixing bowl. Mash with potato masher until almost smooth. In separate bowl, mix milk, cream cheese, sour cream, parsley and garlic with electric mixer until smooth. Pour mixture over potatoes and mix until blended and as smooth as desired. Taste; add salt and pepper as needed.

Spoon mixture into a lightly greased casserole dish. Cover and bake at 325° for 30-40 minutes. Uncover; sprinkle with cheese. Bake an additional 5-10 minutes or until cheese is melted.