Pommes Anna looks like a brown cake 6 to 8 inches in diameter and 2 inches high. A thick, flameproof baking dish of some sort is actually one of the keys to pommes Anna because it must be an excellent heat conductor. A cast iron skillet is recommended.
You want to make sure your potatoes will not stick to the pan because you want to be able to unmold them at the end of cooking. Therefore, use clarified butter, dry the potatoes thoroughly before the cooking begins, and finished the cooking once you have begun or else the potatoes will exude moisture and stick to the pan.
2 sticks of butter
3 pounds “boiling” potatoes
Preheat oven to 450 degrees. Set one rack in the very bottom level, and another just above it. Clarify the butter: melt it, skim off scum, and spoon the clear liquid butter off the milky residue. Peel the potatoes, trim into cylinders about 1 ¼ inches in diameter so that you will have uniform slices, then slice cylinders into even rounds 1/8 inch thick. You should have about 8 cups. Dry thoroughly in paper towel. Do not wash the potatoes after peeling, because you want the starch to remain in, so potatoes will mass more easily into a cake.
Arranging the potatoes in the dish:
Pour ¼ inch of the clarified butter into the pan and set over moderate heat. When hot, start rapidly arranging the first layer of potatoes in the bottom of the pan as follows:
Arrange one potato slice in the center of the pan. Overlap a circle of potato slices around it. Overlapping in the opposite direction rapidly arrange a second circle around the first and continue with another overlapping circle if necessary to rim the edge of the pan. Pour on a spoonful the clarified butter.
Reversin direction again, rapidly arrange an evenly overlapping layer of potatoes around circumference of pan, fill in the center with more potatoes, and baste with another spoonful of butter. Shake pan not too roughly by handle to be sure potatoes are not sticking and sprinkle on salt and pepper.
Continue filling the pan with layers of potatoes basted with butter and seasoned with salt and pepper,, always being sure that the layer around the circumference of the pan is evenly spaced. Remember, also, to shake the pan by its handle from time to time, to be sure potatoes are not sticking. Fill the pan completely, allowing potatoes to form a ¼ to ½ inch dome in the center; they will sink during cooking. You should have added enough butter so that you can see it bubbling up the sides of the pan; excess will be poured out after cooking.
A heavy saucepan, 7 inches in diameter or whatever will fit into the potato pan.
A heavy close fitting cover for the potato pan.
A pizza tray or roasting pan for catching any drippings.
Butter bottom of saucepan and press it down hard on the potatoes, forcing the layers together. Butter underside of cover, place it on the potato pan set on upper of the two oven racks. Set drip pan under the potatoes, on rack below, to catch bubbling butter.
Bake for 20 minutes, uncover, press potatoes down hard again with bottom of saucepan, and continue baking 20 to 25 minutes more uncovered. Press down potatoes again prior to end of baking. Potatoes are done if brown and crusty.