Pre-heat oven to 400°F.

In a medium bowl, mix together gruyere, parmesan, thyme, salt, and garlic.1 ½ cups gruyere cheese, ⅔ cup parmesan cheese, 1 Tablespoon fresh thyme, 1 to 1 ¼ tsp coarse sea salt, 2-4 garlic cloves

In a second large bowl, coat the sliced potatoes with melted butter

(1 1/2 pounds Yukon Gold potatoes, 4 Tablespoon unsalted butter)

In a muffin tin, layer 4 potato slices and then approximately 1/2 teaspoon of the cheese mixture. Continue this pattern of 4 potato slices, then cheese, until the potatoes are taller than the tin (they will shrink when they cook). You'll have 3-4 layers total, ending with cheese on top.

Cover with foil and bake for 15 minutes. Remove foil and continue to bake for an additional 25-30 minutes until golden brown and bubbly. How thinly you sliced your potatoes and how high you stacked will affect the bake time, you want them to be fork-tender with the tops and sides golden brown. Remove potato stacks with a spoon and serve with additional thyme as desired.