Ingredients:

  • 3 lbs Yukon Gold potatoes
  • 1 tbsp unsalted butter
  • 2 cups heavy cream
  • 1 cup whole milk
  • 3 tbsp all-purpose flour
  • 4 tbsp unsalted butter
  • 3 cloves garlic, smashed and peeled
  • 2 tsp fresh thyme leaves, minced
  • 1.5 tsp kosher salt
  • 0.5 tsp black pepper
  • 0.25 tsp ground nutmeg
  • 0.5 cup Gruyère cheese

Instructions:

  1. Preheat and Prep. Set your oven to 350°F (175°C). Grease your 9x13 inch ceramic dish with 1 tablespoon of butter until the bottom and sides are fully coated. Note: This prevents the starch from sticking and burning to the edges.
  2. Make the Roux. Melt 4 tablespoons of butter in a saucepan over medium heat. Whisk in the 3 tablespoons of flour and cook for 2 minutes until it smells slightly nutty but stays pale.
  3. Build the Sauce. Gradually whisk in the milk and heavy cream. Add the smashed garlic, thyme, salt, pepper, and nutmeg. Simmer for 5 minutes until the sauce slightly thickens and bubbles. Note: Do not let it reach a rolling boil or the cream might separate.
  4. Infuse and Strain. Remove the saucepan from the heat. Carefully fish out and discard the three garlic cloves so no one gets a whole clove in their bite.
  5. Slice the Potatoes. Using your mandoline, slice the 3 lbs of Yukon Golds into 1/8 inch rounds. Do not rinse them. Note: The surface starch is our natural thickener.
  6. Layer the Dish. Arrange the slices in the dish, slightly overlapping them like shingles. Pour the warm infused sauce evenly over the potatoes until they are mostly submerged.
  7. Add the Finish. Sprinkle the 0.5 cup of Gruyère cheese over the top if you are using it. It adds a lovely golden crust.
  8. The First Bake. Cover the dish tightly with foil. Bake for 45 minutes until the potatoes are beginning to soften.
  9. The Final Crisp. Remove the foil. Bake for another 30 minutes until the top is golden brown and the sauce is bubbling and thick.
  10. The Essential Rest. Let the dish sit on the counter for 10 minutes before serving. Watch as the sauce sets into a velvety coating. Note: Serving too early results in a runny sauce.