To make these Miso Maple Sweet Potato Stacks, start by preheating your oven to 400F. Wash, dry, and thinly slice your sweet potatoes to about 1/16 of an inch thick, then place them in a large bowl.
In a separate bowl, combine the olive oil, melted butter, maple syrup, white miso paste, mashed garlic, thyme, rosemary, chives, salt, and pepper. Mix well to create your miso maple herb mixture.
Pour the mixture over the sliced sweet potatoes and toss to coat every piece evenly.
Take your muffin tin (either a jumbo pan or a standard 12-slot) and begin layering the potatoes neatly in each slot. Be sure to fill each one a little past the top, as the potatoes will shrink down as they bake.
Cover with foil and bake for 25 minutes. Remove the foil and bake for another 25 minutes, or until they are fork tender and crispy on top.
Optionally, broil for 2 minutes at the very end for even more crispiness on top.
Remove each stack from the muffin pan, top with chopped chives, and serve.