Directions:

1. Place olive oil in an 8- or 9-inch well-seasoned cast iron skillet, and rotate the pan to distribute oil evenly over the bottom.
2. Starting in the center of the skillet, place one slice of potato, then continue placing slices in skillet in concentric, overlapping circles until the bottom of the pan is covered. Brush lightly with melted butter, season with salt and pepper, and sprinkle a little thyme on top. Continue this technique, overlapping circles of buttered, seasoned, herbed potato, until the potatoes are gone. (Please make sure there is no thyme on top!) Press the top surface of the potatoes firmly with a spatula.
3. Preheat oven to 425˚ Place potato-filled skillet on the stove and cook over medium-high heat for 5 minutes, continuing to press down occasionally with spatula. Shake the pan lightly to make sure the potatoes are not sticking to the bottom, then transfer pan to the preheated oven. Bake 40 minutes longer, or until a knife slides through easily in the middle.
4. Let rest 5 minutes, then run a small knife around the pan, loosening any stuck potatoes. Gently place an inverted serving plate or cookie sheet on top of the skillet. Carefully flip over, then cut into wedges and serve.