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, slightly warmed
2 cups sharp cheddar cheese, shredded
1 cup Gruyere cheese, shredded
1/2 cup yellow onion, finely diced
3 cloves garlic, minced
1 teaspoon sea salt
1/2 teaspoon cracked black pepper
1/4 teaspoon ground nutmeg
1/2 teaspoon smoked paprika
Fresh parsley, chopped for garnish
Instructions
Preheat your oven to 375 degrees Fahrenheit. Grease a 9 by 13 inch baking dish generously with butter or a light coating of oil to ensure nothing sticks during the long bake time.
In a medium saucepan, melt the butter over medium heat. Add the finely diced onions and cook for about 5 minutes until they are soft and translucent. Stir in the minced garlic and cook for another minute until the fragrance fills your kitchen.
Whisk the flour into the butter and onion mixture, cooking for 2 minutes to remove the raw flour taste. Slowly pour in the warm milk while whisking constantly to prevent lumps. Continue to cook and stir until the sauce thickens enough to coat the back of a spoon. Remove from heat and stir in the salt, pepper, nutmeg, and half of the shredded cheeses until melted and smooth.
Arrange half of the sliced potatoes in an even layer in the prepared baking dish. Pour half of the cheese sauce over the potatoes, spreading it to the edges. Repeat with the remaining potatoes and the rest of the sauce. Sprinkle the remaining shredded cheese and the smoked paprika over the top.
Cover the dish tightly with aluminum foil and bake for 45 minutes. Remove the foil and continue baking for another 25 to 30 minutes, or until the potatoes are tender when pierced with a fork and the top is golden brown and bubbly. Let the dish rest for 10 minutes before serving to allow the sauce to set.
