Peel the sweet potato, cut off the ends, and slice very thin using a mandoline.
In a bowl, mix oil, nutmeg, thyme and salt.
Lightly brush the 6 cups of a muffin pan with the oil.
Stack the potato slices on top of one another into the muffin pan cups, lightly brushing every second slice with the oil mix. Brush the top slice of each stack with the oil.
Bake the stacks until lightly browned on the edges, 25 to 30 minutes. Test whether or not the stacks are done by pushing a paring knife straight through one of them. If the stack is soft, it is done.
Notes:
*You can use either an orange or a white sweet potato.