Preheat oven to 375°F.
Cook bacon until crispy. (Place on cookie sheet and bake for 18-22 minutes at 415°F) Once cooled, chop into small pieces.
Slice potatoes using a mandolin for uniformity. Be careful to keep the shape of the potato. When using a mandolin, it is best to slice the potatoes right onto the cutting board. (not into a bowl) Set aside.
Layer butter at bottom of cast iron pan. (I used an 8-inch Staub pan)
Carefully set the potato slices (trying to keep the shape of potato together) on top of the butter.
Remove thyme leaves from the stem. Use half on potatoes, reserve remaining for on top after done cooking.
Top with the minced garlic, salt, pepper, 2 cups of the cheese (reserve 1/2 cup of cheese for later), and chopped bacon.
Pour cream over the top of the dish.
Cover with foil and bake for 35 minutes.
Remove dish from oven and remove foil. Add the final 1/2 cup of cheese and return to oven. Bake for an additional 30-40 minutes or until potatoes are tender and the top is golden brown.
Remove from oven and add remaining thyme. Serve immediately.