Ingredients:

  • 2.5 lbs (1.1 kg) Yukon Gold potatoes, peeled and thinly sliced (about 1/8 inch thick)
  • 1 medium yellow onion, thinly sliced
  • 2 cloves garlic, minced
  • 2 tablespoons unsalted butter
  • 2 tablespoons all-purpose flour
  • 2 cups (475 ml) whole milk
  • 1 cup (235 ml) heavy cream
  • 1 teaspoon salt
  • 1/2 teaspoon black pepper
  • 1/4 teaspoon nutmeg (freshly grated is best!)
  • 2 cups (approx. 225g) shredded sharp cheddar cheese
  • 1/2 cup (approx. 55g) grated Gruyere cheese (optional, but adds a lovely nutty flavour)

Instructions:

  1. Slice potatoes thinly. Sauté onion and garlic in butter until softened.
  2. Whisk in flour to create a roux. Gradually whisk in milk and cream. Simmer until thickened. Season with salt, pepper, and nutmeg.
  3. Layer potatoes, cheese, and cream sauce in the prepared baking dish, repeating until all ingredients are used. Ensure the top layer is mostly potatoes covered by cheese.
  4. Cover the dish with foil and bake at 375°F (190°C) for 30 minutes. Remove foil and bake for an additional 20-30 minutes, or until golden brown and bubbly and the potatoes are tender when pierced with a fork.
  5. Let the scalloped potatoes rest for 10-15 minutes before serving. This allows the sauce to thicken slightly.