Potatoes Au Gratin

Potatoes Au Gratin

from insanelygoodrecipes.com
105 min

Rich and creamy, these potatoes au gratin are layered with Gruyère, Parmesan, garlic, and fresh thyme, making each bite irresistibly cheesy and flavorful!

Ingredients

  • 2 cups heavy cream
  • 1/4 cup unsalted butter, melted
  • 3 cloves garlic, minced
  • 2 teaspoons fresh thyme leaves
  • 1 teaspoon salt
  • 1/2 teaspoon black pepper
  • 2 1/2-3 pounds Russet or Yukon Gold potatoes
  • 1/2 yellow onion
  • 1 1/2 cups grated Gruyère cheese
  • 1/2 cup grated Parmesan cheese

Directions

  1. 1

    Preheat the oven to 375 degrees Fahrenheit. Butter a 9x13-inch baking dish or a deep, medium-sized casserole dish. Set aside.

  2. 2

    In a medium saucepan, combine the heavy cream, butter, garlic, thyme, salt, and black pepper. Warm over low heat until the butter melts, stirring occasionally. Remove from the heat.

  3. 3

    Peel and thinly slice the potatoes and onion. They should be even and about 1/8-inch thick. For the best results, use a mandolin.

  4. 4

    Arrange about a third of the sliced potatoes and onions evenly in the baking dish. Pour a third of the cream mixture over the potatoes, allowing it to seep in. Then, sprinkle a third of the Gruyère cheese on top.

  5. 5

    Repeat these layers until the dish is full, but do not add the top layer of cheese yet. Instead, cover the dish with foil.

  6. 6

    Bake for 75-90 minutes, or until the potatoes in the middle are tender.

  7. 7

    Remove the dish from the oven and take off the foil. Add the last of the Gruyère cheese and the Parmesan, then bake again (uncovered) for about 15 minutes. The cheese should be golden and bubbly.

  8. 8

    Let the dish stand for 10-15 minutes before serving to allow the sauce to set. Garnish with fresh herbs if desired, and enjoy.