- 3 Pounds Yukon Gold Potatoes, Peeled (optional) And Sliced ⅛-Inch Thick
- 2 Cup Shredded Sharp Cheddar Cheese, Divided
- 1 Cup Grated Parmesan Cheese
- 1 Cup Grated Asiago Cheese
- 4 Tablespoons Butter
- 1 Medium Onion, Diced
- 4 Cloves Garlic, Minced
- 3 Tablespoons All-Purpose Flour
- 3 Cups Half N Half
- 1 Teaspoon Kosher Salt
- ½ Teaspoon Black Pepper
- ¼ Teaspoon Grated Nutmeg
- 1½ Tablespoons Fresh Thyme, Divided
- Preheat the oven to 400°F Grease a 9×13 baking dish with butter and set aside.
- Using a mandoline slicer or a sharp knife, slice the potatoes to ⅛-inch thick. (If you’re using a knife, try to cut the slices as evenly as possible.
- Spread a third of the sliced potatoes in an even layer in the prepared baking dish.
- In a small bowl, combine the cheeses and mix them well. Reserve 1 cup for the topping and set it aside.
- Prepare the sauce: in a large sauté pan over medium-high heat, melt the butter. Add the onion and cook until it’s translucent, about 4-5 minutes. Add the garlic and cook until it’s fragrant, about 30 seconds. Add the flour and stir while cooking for another 1 – 2 minutes. Add the Half N Half, salt, pepper, nutmeg and 1 tablespoon of the thyme. Bring to a simmer and whisk until combined and thickened. Add the 1¾ cups of the cheese blend and stir until the cheese is melted and the ingredients are completely mixed. Turn off the heat and set the sauce aside.
- Pour a third of the cheese sauce over the potatoes, and spread it out evenly with a spatula. Spread the next third of potatoes in the baking dish and top it with another third of cheese sauce. Repeat the layering process with the remaining potatoes and sauce. Top the final layer of sauce with the reserved ¾ cup of cheese.
- Cover the baking dish with foil and bake for 30 minutes. Remove the foil and bake uncovered for an additional 25 -30 minutes, or until the potatoes are cooked through and the sauce is bubbling. Sprinkle with the remaining fresh thyme and serve warm.