Layered Potatoes With Garlic Herb Butter

Rub thyme between fingers to release oils and then place in a saucepan. Add butter, garlic, salt, and pepper. Cook over medium, stirring often, until butter melts, 3 to 4 minutes. Remove from heat. Let stand for 15 minutes.

Meanwhile, preheat oven to 400 F. Thinly slice Yukon Gold and sweet potatoes into 1/16-inch-thick slices, preferably using a mandoline.

Remove sprigs from the butter and discard. Reserve 1 tablespoon herb butter in a small bowl and set aside.

Brush the bottom of a large ovenproof or cast-iron skillet with some remaining herb butter. Cover the bottom of the skillet with a layer of sliced Yukon Gold and sweet potatoes, starting from the center and working outward in concentric circles, overlapping slices.

Generously brush the top with more herb butter. Repeat layering with remaining potato slices, brushing with herb butter after each layer. (You'll have about six layers.)

Heat the skillet over medium-high until the mixture is sizzling, 2 to 4 minutes. Carefully cover with aluminum foil and then transfer the skillet to the oven and bake for 15 minutes.

Remove the foil. Continue baking, rotating the skillet halfway through, until the center is tender when pierced with a wooden pick and some potato slices on top curl and darken, about 45 minutes.

Brush with reserved 1 tablespoon herb butter and continue baking for 5 minutes. Let cool for about 15 minutes.

Run a rubber spatula around the edges of the skillet to loosen it, gently sliding the spatula underneath. Slice into wedges while in the skillet and top with thyme leaves.