Thanks to Smitten Kitchen for this amazing recipe.
65 grams finely grated aged Pecorino Romano
10 grams) cornstarch
1/2 teaspoon fine sea
1/2 teaspoon finely ground black pepper
45 grams unsalted butter, melted
2 pounds Yukon Gold potatoes, peeled, cut into 1/8-inch-thick
Heat your oven to 375°F. Combine the cheese, cornstarch, salt, and pepper in a small dish.
Pour 1 tablespoon butter or oil into the bottom of a 9-inch-diameter cast-iron or ovenproof skillet, and swirl it up the sides. Arrange the potatoes in overlapping concentric circles in a single layer at the bottom of the pan. (This will use approximately a quarter of your sliced potatoes.) Drizzle with 1 teaspoon butter and sprinkle with 2 tablespoons of the cheese-pepper mixture. Repeat this three or four times to use up your potatoes. At the end, you should have about 1 tablespoon cheese-pepper mixture left over; reserve this. Drizzle any remaining melted butter over the top.
Lightly coat a piece of foil with nonstick spray and cover the skillet tightly with it. Put in heated oven for 35 minutes. Use potholdered hands to press firmly on the foil to compact the potatoes a bit. Remove and reserve the foil and bake for 25 to 30 minutes more, until lightly brown all over. Press again with the foil, remove, then briefly run under the broiler for an even golden-brown finish.
Once the galette is out of the oven, let it rest in the skillet for a few minutes before running a knife around to ensure that it is loose. Gently tip the skillet over your sink to drain any excess butter or oil. Invert it onto a plate and sprinkle with leftover cheese and pepper.