# Needed Ingredients:
→ Potatoes
01 - 4.5 lbs russet potatoes, peeled and thinly sliced
→ Dairy
02 - 3 cups whole milk
03 - 1 cup heavy cream
04 - 3 cups sharp cheddar cheese, shredded
05 - 1 cup Gruyère cheese, shredded
06 - 4 tbsp unsalted butter
→ Flavorings
07 - 1 medium yellow onion, finely diced
08 - 3 garlic cloves, minced
09 - 1 tsp salt
10 - ½ tsp black pepper
11 - ½ tsp paprika
12 - ¼ tsp ground nutmeg
→ Topping
13 - ½ cup Parmesan cheese, grated
14 - 2 tbsp fresh parsley, chopped (optional)
# Preparation Steps:
01 - Preheat oven to 375°F and grease a 9x13-inch baking dish with butter.
02 - In a medium saucepan over medium heat, melt butter. Add diced onion and cook until translucent, approximately 4 minutes, then add minced garlic and cook for 1 minute.
03 - Incorporate flour into the saucepan, cooking for 1 minute while stirring. Gradually whisk in whole milk and heavy cream, then season with salt, black pepper, paprika, and nutmeg. Cook while whisking frequently until sauce thickens, about 4 to 5 minutes.
04 - Remove sauce from heat and stir in 2 cups shredded cheddar and all Gruyère cheese until fully melted and smooth.
05 - Arrange half of the sliced potatoes in the prepared dish, overlapping slightly. Pour half of the cheese sauce evenly over the potatoes. Repeat with remaining potatoes and sauce.
06 - Evenly sprinkle the remaining 1 cup shredded cheddar and grated Parmesan over the top layer.
07 - Cover loosely with aluminum foil and bake for 40 minutes. Remove foil and continue baking for an additional 20 minutes until the surface is golden, bubbly, and potatoes are tender when pierced with a fork.
08 - Allow to rest for 10 minutes before serving. Garnish with chopped fresh parsley if desired.
