Potato and Onion Gratin

This makes for a satisfying, comforting weekend dish, or it’s also great for the holidays.

Serves: 4Hands-on: 10 minutesTotal: 1 hourDifficulty: Easy

Serves: 4


  • 1⁄2 cup milk
  • 1 tsp. sea salt
  • 1⁄2 tsp. ground black pepper
  • 2 Tbsp. butter, cut into pieces, plus more for buttering
  • 1 lb. Yukon Gold potatoes, sliced very thin
  • 1 large yellow onion, sliced thick
  • 1⁄2 cup grated Parmesan cheese
  • 1 Tbsp. fresh thyme leaves


  • Preheat oven to 400°F and place a rack in the middle. In a medium bowl whisk together milk, salt, and pepper. Set aside.
  • Grease a 9-by-13-inch baking dish with butter. Layer about half of potato slices evenly on bottom. Top with onion, then with half of Parmesan. Layer remaining potatoes on top and sprinkle with remaining Parmesan.
  • Pour milk mixture over potatoes. Sprinkle on thyme. Scatter butter pieces on top of potatoes.
  • Bake, covered with aluminum foil, 25 minutes. Remove foil and bake another 25 minutes or until potatoes are tender and cheese is golden brown.