Ingredients:

  • 3 lbs Yukon Gold potatoes, peeled and cubed
  • 1/2 cup unsalted butter, softened
  • 1 cup whole milk, warmed
  • 8 oz Gruyère cheese, shredded
  • 1 tsp kosher salt
  • 1/2 tsp cracked black pepper
  • 1 lb Russet potatoes, thinly sliced (1/8 inch)
  • 3 tbsp melted butter
  • 3 cloves garlic, minced
  • 1 tsp fresh thyme leaves
  • 1/2 cup Parmesan cheese, freshly grated
  • 1/2 cup Panko breadcrumbs
  • 2 tbsp melted butter
  • 1/2 cup sharp Cheddar cheese, shredded

Instructions:

  1. Place cubed Yukon Gold potatoes in cold salted water. Bring to a boil and simmer until fork-tender (about 15-20 minutes).
  2. Drain potatoes thoroughly and let them steam-dry in the pot for 2 minutes to remove excess moisture.
  3. Pass the potatoes through a ricer or mash by hand until smooth to avoid a gummy texture.
  4. Fold in the softened butter and warmed milk until the mixture is velvety.
  5. Stir in the shredded Gruyère, salt, and pepper until the cheese is fully melted and incorporated.
  6. Preheat your oven to 400°F (200°C) and grease a 9x13 inch baking dish with butter.
  7. Spread the mashed potato mixture evenly into the bottom of the dish, smoothing the top with a spatula.
  8. In a bowl, toss the thinly sliced Russet potatoes with 3 tbsp melted butter, minced garlic, and fresh thyme.
  9. Layer the sliced potatoes evenly over the mashed potato base.
  10. Combine Panko breadcrumbs, grated Parmesan, and shredded Cheddar. Spread the mixture over the potato slices and drizzle with the final 2 tbsp of melted butter.
  11. Bake for 40-60 minutes until the crust is mahogany-colored and crisp.