Start by making the cream sauce for the potatoes. In a large sauce pan over medium high heat, melt the butter then add in the flour. Whisk until the flour is fully incorporated and you don’t see any more white. Add in the milk and cream and whisk to be sure the roux (flour and butter mixture) is mixed into the liquid. Add in the grated garlic, nutmeg and poultry seasoning along with some salt and pepper. Let this come to a light simmer whisking periodically, remove from heat, taste for seasonings and then set aside.

Preheat your oven to 375 F, then mix all the shredded cheeses together. Peel and slice your potatoes into about 1/8 inch using a mandolin or by hand – be very careful! Layer a 9×13 baking dish with the first amount of sliced potatoes, slightly stacking them as you go. Make sure the entire bottom of the dish is covered. Ladle on about 1/3 of the cream mixture and about 1/3 of the shredded cheese mixture. Repeat this step until you have 3 layers and end up with the cream mixture then the cheese on top. Cover the entire dish with aluminum foil and bake for 45 minutes to an hour, or until the potatoes are fork tender. Once tender, remove the foil and continue baking until the top turns golden brown and bubbly, about another 15-20 minutes. Depending on your oven, you can also broil it here for 2-3 minutes to achieve a golden brown color if you choose. Remove from oven and let cool 10-15 minutes before serving. Enjoy!