Ingredients:

  • 1.4 kg (3 pounds) Russet or Yukon Gold potatoes, peeled and thinly sliced (about 1/8 inch / 3mm thick)
  • 1 tablespoon olive oil
  • 2 tablespoons unsalted butter
  • 2 cloves garlic, minced
  • 2 tablespoons all-purpose flour
  • 600 ml (2 ½ cups) 1% or 2% milk
  • 120 ml (½ cup) low-sodium chicken or vegetable broth
  • ½ teaspoon dried thyme
  • ¼ teaspoon freshly grated nutmeg
  • Salt and freshly ground black pepper to taste
  • 60g (½ cup) grated Gruyère or sharp white cheddar cheese
  • 2 tablespoons fresh parsley, chopped

Instructions:

  1. Prepare the Oven and Baking Dish: Preheat your oven to 375°F (190°C). Lightly grease a 9x13 inch (23x33 cm) baking dish with 1 tablespoon of olive oil.
  2. Prepare the Potatoes: Peel and thinly slice the Russet or Yukon Gold potatoes into 1/8 inch (3mm) thick rounds, preferably using a mandoline for consistency. Set aside. Uniformly thick slices are crucial for even cooking.
  3. Make the Cream Sauce: In a large saucepan or skillet, melt 2 tablespoons of unsalted butter over medium heat. Add the minced garlic and sauté for 1 minute until fragrant, being careful not to brown it.
  4. Form the Roux: Whisk in 2 tablespoons of all-purpose flour and cook for 1-2 minutes, stirring constantly, to create a light roux.
  5. Add Liquids and Thicken: Gradually whisk in the 600 ml of 1% or 2% milk, followed by the 120 ml of low-sodium chicken or vegetable broth. Continue whisking until the sauce begins to thicken, about 5-7 minutes.
  6. Season the Sauce: Stir in ½ teaspoon of dried thyme and ¼ teaspoon of freshly grated nutmeg. Season with salt and freshly ground black pepper to taste. Remove from heat.
  7. Assemble the Scalloped Potatoes: Arrange a layer of sliced potatoes in the bottom of the prepared baking dish. Pour about one-third of the cream sauce over the potatoes. Avoid over-saucing the bottom layer. If using, sprinkle a portion of the 60g of grated Gruyère or sharp white cheddar cheese over the sauce layer. Repeat the layering process twice more, ending with a final layer of sauce and cheese on top.
  8. Bake: Cover the baking dish with aluminum foil and bake for 60 minutes.
  9. Brown and Finish: Remove the foil and continue baking for an additional 15 minutes, or until the potatoes are tender, the sauce is bubbling, and the top is golden brown and slightly caramelized.
  10. Rest and Serve: Let the scalloped potatoes rest for 10-15 minutes before serving. Garnish with 2 tablespoons of fresh chopped parsley, if desired.