Ingredients

• 3 lbs russet potatoes, cleaned (not peeled)
• 3 tbsp butter, divided
• 8 oz Gruyere cheese, grated
• 3 oz Parmesan cheese, grated
• 2½ cups heavy cream
• 1 cup whole milk
• 5 cloves garlic, minced
• 1 shallot, chopped
• 6 strips bacon, chopped
• 3 leeks, cleaned and sliced thinly
• 1 sprig fresh rosemary
• 1 sprig fresh thyme
• Seasonings:
  • ¾ tsp nutmeg
  • 1 tsp salt
  • ¾ tsp freshly ground black pepper
• Toppings**:**
  • 3 tbsp fresh chives, chopped
  • Gluten-Free Breadcrumbs (optional, for a drier interior after layering)

Instructions

1. Prepare the Oven and Dish:
   • Preheat the oven to 390°F.
   • Grease the sides and bottom of a baking dish with 1 tbsp butter.
2. Prepare the Potatoes:
   • Use a mandolin to thinly slice the potatoes.
   • Place the slices in a bowl of cold water as you cut to prevent browning.
   • Pat the slices dry with a clean towel before layering.
3. Cook the Aromatics:
   • In a skillet, cook the chopped bacon until slightly crisp.
   • Add 1 tbsp butter, then stir in the shallots, leeks, and garlic. Sauté until lightly browned.
4. Prepare the Cream Mixture:
   • In a saucepan over low heat, combine 2 tbsp butter, heavy cream, milk, rosemary, and thyme.
   • Use an immersion blender to mix the cream mixture until smooth.
   • Stir in the nutmeg.
5. Combine Aromatics with Cream:
   • Remove the herbs from the cream mixture.
   • Stir the cooked bacon, shallots, leeks, and garlic into the cream.
6. Layer the Gratin:
   • Place a single layer of sliced potatoes in the greased baking dish.
   • Sprinkle lightly with salt and pepper, then drizzle with the cream mixture.
   • Repeat the layering process, leaving about ½ inch of space at the top of the dish for the cheese topping.
7. Bake:
   • Cover the dish with foil and bake at 390°F for 45 minutes.
   • Remove the foil, sprinkle the top evenly with Gruyere and Parmesan cheese, and bake for an additional 25 minutes.
8. Finish and Serve:
   • Top the gratin with chopped chives.
   • Let it rest for a few minutes before serving to allow the layers to set.