Thinly slice 3 or so large, peeled sweet potatoes. You want little rounds. Using a vegetable peeler is not a bad idea. Submerge these in cold water if they start to go black on you too quickly. Melt butter, about half a cup. Brush a little of this on the bottom of a pie pan--springform is best if you've got it. then create a nice spiraling layer of potato on the bottom. Atop this, brush more butter, a little nutmeg, and some freshly grated parmesan. I only use parmagiano reggiano, which is exqusite in this. Salt and pepper, if you like. Then do another layer of potato, and repeat until all ingredients are utilized.
Bake, covered in foil, for 45 minutes in a 425 degree oven, then uncover and bake about a half-hour, or till crusty and delicious looking.
