In a 13×9-inch baking dish, stir together potatoes, butter, thyme, garlic, salt, and pepper; spread in an even layer.
Bake until potatoes are fork-tender, 45 to 50 minutes.
Transfer potatoes, melted butter, and seasonings in pan to a large bowl. Using a potato masher, mash potatoes to desired consistency. Stir in warm milk and broth or reserved drippings. Keep warm until ready to serve.
Recipe by Paula Deen Magazine at https://pauladeenmagazine.com/oven-roasted-mashed-potatoes-recipe/