Preheat the oven to 425 degrees F.

Slice the potatoes using a mandolin slicer or a food processor to thin even slices—as thin as you can, around 1/16th of an inch thick. Alternatively, slice them by hand as thin and uniform as you possibly can.

Line each cavity of a muffin pan with aluminum foil and make sure the bottom and walls of the cavity are covered.

Stack up the potato slices in each muffin cavity alternating colors and fill up the muffin pan about 3/4th f the way.

In a large measuring cup, Add in the hot milk, garlic, thyme, parmesan cheese and seasoning. Whisk the milk mixture well.

Pour the milk mixture evenly over the potatoes and cover them up with a layer of foil.

Bake the potatoes for 20 minutes until the are fork tender, then uncover the potatoes and bake 3-5 mins more until no more liquid is there.

Allow the potatoes to cool down for 5 minutes before unfolding them from the foil and serving them. It’s best to remove each potato gratin from the pan with its foil lining and then tear apart the foil.

Sprinkle extra Parmesan on top of each mini potato gratin.