Preheat oven to 425°F.
Using a mandoline, thinly slice the sweet potatoes, about ¼ inch thick, leaving the skin still on.
In a small 6-inch cast iron skillet or baking dish, shingle the potatoes in a circle, one next to the other. Place a few smaller ones in the middle. Next, tuck some rosemary leaves between every 5 or 6 slices. Make sure to wedge them about halfway down.
Next, in a small sauce pot melt the butter with the oil. Add in the garlic, a large pinch of salt and a little pepper. Stir to combine and finish with some freshly grated nutmeg. Once the butter has melted, pour the mixture over the potatoes.
Bake for 40-45 minutes or until the potatoes are cooked through, a toothpick should easily pierce the flesh, and are slightly crispy on top. Check every so often to make sure they aren’t burning.
Recipe Courtesy of Megan Mitchell