Ingredients:

  • 4 tbsp unsalted butter
  • 1/4 cup all-purpose flour
  • 2 cups half-and-half
  • 2 cloves garlic, minced
  • 1/2 tsp salt
  • 1/4 tsp ground black pepper
  • 2 lbs russet potatoes, peeled
  • 1 tbsp melted butter
  • 1 1/2 cups sharp cheddar, shredded
  • 1 cup fontina cheese, shredded
  • 1/2 cup parmesan cheese, freshly grated

Instructions:

  1. Slice the peeled potatoes into 1/8 inch thick rounds using a mandoline or sharp knife. Note: Uniform thickness ensures they all cook at the same rate.
  2. Grease a 9x13-inch baking dish with 1 tbsp melted butter. Note: This ensures the edges caramelize and don't stick to the sides.
  3. Layer half of the sliced potatoes in the bottom of the dish, overlapping them slightly like shingles.
  4. Melt 4 tbsp butter in a saucepan over medium heat. Whisk in the flour and cook for 1-2 minutes until it smells slightly nutty but stays pale.
  5. Slowly pour in the half and half, whisking constantly. Note: Do this in a slow stream to eliminate lumps.
  6. Stir in the minced garlic, salt, and pepper. Simmer on low for 3-5 minutes until the sauce is thick enough to coat the back of a spoon.
  7. Remove the saucepan from heat and stir in the shredded cheddar and fontina cheese until the sauce is glossy and smooth.
  8. Pour the cheese sauce evenly over the first layer of potatoes.
  9. Layer the remaining potatoes on top and pour the remaining sauce over the surface, smoothing it with a spatula.
  10. Sprinkle the grated parmesan cheese evenly across the top.
  11. Bake at 375°F (190°C) for 40-45 minutes until the top is a deep mahogany gold and the sauce is bubbling.