To make these Herby Potato Stacks, start by preheating your oven to 400F. Wash, dry, and thinly slice your Yukon gold 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, mashed garlic, thyme, rosemary, parsley, salt, and Parmigiano Reggiano cheese. Mix well to create your herb and butter mixture.
Pour the mixture over the sliced 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.
Sprinkle the tops with black pepper, then cover the pan with foil. Bake for 25 minutes. Remove the foil and bake for another 25 minutes, or until the potatoes are fork tender and the tops are golden and crispy.
If you’d like even crispier edges, broil for about 2 minutes at the end. Carefully remove each stack from the muffin pan, sprinkle with extra cheese and chopped chives, and serve immediately.