Peel the potatoes. There should be about 4 1/2 pounds when peeled. Drop the potatoes into cold water until ready to cook. Bring enough water to boil to cover the potatoes when they are added. Add salt to taste. Add potatoes and cook 25 minutes, or until they are slightly undercooked. They will cook later in the oven.
Meanwhile preheat oven to 450 degrees. Drain the potatoes and put them in a large heavy skillet. Sprinkle generously with pepper and add 16 tablespoons of butter. Using a large heavy spoon, cut the potatoes haphazardly into chunks, each about 2 inches thick. Let them cook 12 to 15 minutes, turning the pieces over so that they brown evenly. Meanwhile, heat a large heavy skillet (preferably a 12-inch, number 10 black iron skillet) until it is hot and almost smoking. Melt the remaining 8 tablespoons of butter in a saucepan and pour it into the skillet. Add 1 tablespoon of the garlic and the potato mixture, mix together and then flatten it on top with a large heavy metal spoon. Let cook moderately high heat for three minutes. Place the skillet in the oven and bake 15 minutes.
Remove form the oven and pour off the free butter from around the sides, taking care not to let the potatoes fall form the skillet (this butter may be recycled and put to other uses, such as scrambling eggs). Cover the skillet with a heat proof round dish, such as a pizza pan. Invert the skillet onto the pan, allowing the potatoes to fall evenly on the pan. Place the pan in the oven and bake 15 minutes longer. Pour off any free-flowing butter from the pan. Carefully slide the pie from the pizza pan or other pan onto a round serving dish. Sprinkle the garlic into a circle in the center of the pie, garnish around the circle of garlic with an outer circle of chopped parsley. Serve with the perfect roasted chicken, T-bone or roasted lobster