Preheat oven to 375°F and grease two cast iron pans completely with butter.
In a large pan over medium high heat, melt butter.
Once the butter has melted, add in the flour, and cook while stirring for a minute or two. Then, gently and slowly add in half-and-half, mixing continuously to ensure there are no lumps.
Once the half and half has been added and it's smooth, lower the heat to medium and add in garlic, fresh herbs, nutmeg, salt, and pepper. Stir together and allow fresh herbs to infuse for a couple of minutes.
In a separate bowl, mix the Mozzarella, Provolone, and grated Parmesan cheese.
Working in layers, place potato slices slightly overlapping in a circular pattern to cover the bottom of both pans. Then, cover each layer with some of the cream mixture, and thin layer of the cheese mixture.
Repeat this process until you fill ¾ of each pan. Cover with the remaining cream mixture. Reserve a layer of cheese for both pans and set aside.
Cover both pans with aluminum foil and bake for 40 minutes. After 40 minutes, remove the foil and top potatoes in each pan completely with the remaining layer of cheese.
Raise the oven temperature to broil, and return both pans to the oven, uncovered. Bake an additional 10 minutes or until cheese has melted and starts to lightly brown on the edges. Garnish with fresh herbs and red chili pepper flakes and serve hot.