3 pounds Yukon Gold potatoes, peeled and sliced into 1/8 inch rounds
1/4 cup unsalted butter
1/4 cup all-purpose flour
3 cups whole milk
1 teaspoon salt
1/2 teaspoon black pepper
1/2 teaspoon garlic powder
1/2 teaspoon onion powder
1/4 teaspoon ground nutmeg
1/2 cup grated Parmesan cheese
1 tablespoon fresh parsley, chopped for garnish
Instructions
Preheat your oven to 350 degrees Fahrenheit. Lightly grease a 9×13 inch baking dish with butter or a light coating of oil to ensure the potatoes do not stick to the sides during the long baking process.
In a medium saucepan, melt the butter over medium heat. Once the butter is bubbling, whisk in the all-purpose flour and cook for about one minute until the mixture is pale gold and smells slightly nutty, which removes the raw flour taste.
Slowly pour in the milk while whisking constantly to prevent lumps from forming. Add the salt, black pepper, garlic powder, onion powder, and ground nutmeg. Continue to cook and stir until the sauce thickens enough to coat the back of a spoon, then remove from heat and stir in the Parmesan cheese.
Place half of the sliced potatoes in an even layer at the bottom of the prepared baking dish. Pour half of the creamy sauce over the potatoes, spreading it to the edges. Repeat with the remaining potatoes and the rest of the sauce, ensuring the top layer is well covered.
Cover the dish tightly with aluminum foil and bake for 40 minutes. Remove the foil and continue baking for another 20 to 25 minutes, or until the potatoes are tender when pierced with a fork and the top is beautifully golden brown. Let the dish rest for 10 minutes before serving to allow the sauce to set.
