Ingredients:

  • 3 lbs Yukon Gold potatoes, sliced 1/8-inch thick
  • 2 cups cooked ham, cubed
  • 1 medium yellow onion, sliced into translucent rings
  • 2 cups heavy cream
  • 1 cup whole milk
  • 3 cloves garlic, smashed and minced
  • 1 tsp fresh thyme leaves
  • 1/2 tsp ground nutmeg
  • 2 cups sharp white cheddar cheese, freshly grated
  • 1/2 cup Gruyère cheese, grated
  • 1/2 tsp fresh cracked black pepper
  • 1 tbsp unsalted butter (for greasing dish)

Instructions:

  1. Preheat and Slice: Set your oven to 375°F (190°C). Use a mandoline to slice the Yukon Gold potatoes into 1/8 inch rounds. Note: Do not rinse or soak the potatoes to preserve the starch.
  2. Steep the Liquid: In a large saucepan over medium heat, combine heavy cream, whole milk, minced garlic, and fresh thyme.
  3. Simmer Gently: Bring the mixture to a bare simmer until tiny bubbles form around the edges, then remove from heat to steep.
  4. Prepare the Dish: Butter a 9x13-inch ceramic baking dish thoroughly.
  5. First Layer: Arrange one third of the potato slices in an overlapping pattern. Scatter half of the ham and onion rings over the potatoes.
  6. Build the Layers: Repeat the layers, finishing with a final decorative layer of potatoes on top. Season with cracked black pepper.
  7. Add the Sauce: Pour the warm cream mixture over the potatoes.
  8. First Bake: Cover the dish tightly with aluminum foil. Bake for 45 minutes until the potatoes are just tender when pierced with a fork.
  9. The Cheese Topping: Remove the foil, sprinkle with grated cheddar and Gruyère cheeses.
  10. Final Bake: Bake for an additional 25-30 minutes until the top is golden and bubbling.