Preheat oven to 375?F.

Slice potatoes using a mandolin for uniform thickness (about ?-inch thick). Set aside.

Layer the sliced butter in the bottom of a 12-inch cast-iron skillet.

Carefully stack and layer the sliced potatoes over the butter.

Strip the leaves from 2 sprigs of thyme and sprinkle over the potatoes. Reserve remaining thyme for garnish.

Sprinkle garlic, salt, pepper, 2 cups of shredded cheese, and chopped bacon evenly over the potatoes.

Pour the heavy cream evenly over the top.

Cover the skillet tightly with aluminum foil and bake for 35 minutes.

Remove the foil, sprinkle the remaining ? cup of cheese on top, and return to the oven. Bake for an additional 30?40 minutes, or until potatoes are tender and the top is golden brown.

Remove from the oven, garnish with remaining thyme leaves, and serve immediately.