Step 1

Preheat the oven 400 degrees F.

Step 2

Use a mandolin to thinly slice potatoes. It's okay if some come out in half slices.

Step 3

In a large bowl, combine the potatoes, gruyere cheese, parmesan, french onion soup mix, thyme, garlic, and salt. Toss to coat well.

Step 4

Drizzle over the butter and toss to coat.

Step 5

In a muffin tin, divide the potato mixture between the 12 muffin cups. Stack the potatoes above the top of each tin. Make sure to get the cheese between the potato slices. You don't need cheese between every single layer. But make sure there is some cheese distributed throughout the stacked potatoes.

Step 6

Tent with foil (don't let the foil stick to the cheese on top!)

Step 7

Bake for 15 minutes.

Step 8

Remove the foil. Bake for another 20-30 minutes, or until you can stick a toothpick or knife through easily.

Step 9

Use a butter knife or fork and run along the sides of the potato stacks to get them out.