In a pot, cover potatoes with cold water and bring to boil. Cook until fork-tender, about 15 minutes; drain. Add potatoes, butter, 1 1/2 tsp. salt and 3/4 tsp. pepper to large bowl; using a jerking motion, flip until coated and slightly softened. Spread on baking sheet and roast at 425 degrees until a golden crust forms, 20 minutes.