Ingredients:
- 3 lbs Yukon Gold or Russet potatoes, peeled and thinly sliced
- 1 tbsp melted butter (for greasing the pan)
- 3 tbsp unsalted butter
- 3 tbsp all-purpose flour
- 2 cups whole milk, room temperature
- 1 cup heavy cream
- 3 cloves garlic, minced
- 1 tsp kosher salt
- ½ tsp ground black pepper
- ¼ tsp ground nutmeg
- 2 cups sharp cheddar cheese, shredded
- ¼ cup grated Parmesan (optional)
Instructions:
- Preheat your oven to 375°F (190°C). Grease your baking dish with melted butter. Note: Coating the sides prevents the cheese from sticking.
- Slice your potatoes into uniform rounds about 1/8 inch thick. Note: Consistency ensures they all cook at the same rate.
- In a saucepan over medium heat, melt the butter. Whisk in the flour and cook for 1-2 minutes until it smells nutty but hasn't browned.
- Slowly pour in the milk and heavy cream, whisking constantly to eliminate lumps. Stir in the minced garlic, salt, pepper, and nutmeg. Simmer for 5 minutes. Note: The simmer activates the flour's thickening power.
- Layer half of the sliced potatoes in the dish. Sprinkle with half of the cheddar cheese. Pour half of the cream sauce over the top.
- Repeat with the remaining potatoes, cheese, and sauce. Note: Gently press the potatoes down so they don't curl up.
- Top with the final layer of cheese (and Parmesan if using). Cover with foil and bake for 40 minutes.
- Remove the foil and bake for another 20-30 minutes until the top is bubbling and mahogany colored.