Preheat oven to 425°F degrees and place oven rack in center position. Place the Flexipan® Mold of Choice on the Perforated Baking Sheet and set aside.
Thinly slice potatoes using your Mandoline.
In bottom of mold, sprinkle approximately 1/3 of shredded cheese, then 1/3 of potato slices, overlapping as necessary. Sprinkle with salt, pepper and a touch of garlic powder.
Top with 1/3 of cheese and drizzle with 1 tablespoon of butter. Layer 1/3 of potato slices and sprinkle with salt and pepper. Top with 1 tablespoon herb blend, remaining cheese and 1 tablespoon butter. Layer remaining potato slices and drizzle final tablespoon of butter on top. Press mixture down firmly. Bring milk to a boil and pour over potato mixture.
Bake for 45 minutes. Cool for 15 minutes before unmolding.
Garnish with fresh rosemary sprigs and enjoy!