Ingredients:

  • 3 lbs Russet or Yukon Gold potatoes, peeled and thinly sliced
  • 1 tsp Kosher salt
  • 1/2 tsp Black pepper
  • 4 tbsp Unsalted butter
  • 1/4 cup All-purpose flour
  • 3 cups Whole milk, warmed
  • 2 cups Gruyère cheese, freshly grated
  • 2 cloves Garlic, minced
  • 1/4 tsp Nutmeg
  • 1/2 cup Parmesan cheese

Instructions:

  1. Slice potatoes into uniform 1/8 inch rounds. Keep them in a bowl of cold water to prevent browning, then pat them completely dry with paper towels. Toss the dry slices with salt and pepper. Note: Drying them ensures the sauce clings instead of sliding off.
  2. Melt the butter in a medium saucepan over medium heat. Whisk in the flour and cook for 2 minutes until you smell a slightly nutty aroma.
  3. Slowly pour in the warmed milk, whisking constantly until the sauce thickens and becomes velvety.
  4. Remove the pan from heat and stir in the grated Gruyère, minced garlic, and nutmeg until completely melted and smooth.
  5. Grease your 9x13 inch baking dish. Layer the bottom with potato slices, then pour a portion of the cheese sauce over them.
  6. Repeat the layering process until all potatoes and sauce are used, ensuring the top layer is fully covered in sauce.
  7. Sprinkle the top with Parmesan cheese. Cover the dish tightly with foil.
  8. Bake at 350°F (175°C) for 45 minutes until the potatoes are tender when pierced with a knife.
  9. Remove the foil and bake for an additional 30 minutes until the top is mahogany colored and bubbling.