The best Cast-Iron Potato Gratin in the field it came from and topped with finely chopped chives

Cast-Iron Potato Gratin

  • Author: Foodterra
  • Prep Time: 15 minutes
  • Cook Time: 50 minutes
  • Total Time: 1 hour 5 minutes
  • Yield: serves 4 1x


However you slice it, gratin dauphinoise, like the French, or scalloped potatoes, in the Midwest, this luxuriously creamy potato gratin, topped with a golden brown crown of Gruyère and Comté, is comfort food at its best. It would be rude not to add this to your repertoire of sides. It serves up flawlessly with a juicy steak, a bold red wine or deboned chicken. What more could you want?



  • Olive oil, as needed
  • 45 tablespoons unsalted butter
  • 2 leeksgreen parts removed, white parts quartered lengthwise, soaked in water to remove dirt, and chopped into thin half moons
  • ½ shallot, finely chopped
  • 34 cloves garlicminced
  • salt and freshly ground black pepper, season as you go
  • 34 cups whole milk
  • ½ cup heavy cream (optional)
  • 45 large potatoes, we used Purple Vikings, Russets also work well, peeled and cut crosswise into ¼-inch-thick slices using a mandolin
  • 23 teaspoons freshly grated nutmeg
  • 1 cup grated Gruyère cheesepreferably cave aged
  • 1 cup grated Comté cheesepreferably cave aged
  • 1 small bunch chivesfinely chopped


  1. Preheat a heavy-bottomed enameled pot over medium to medium-high heat. Generously coat pot with oil, followed by 3–4 tablespoons butter. Stir until butter is melted and incorporated into oil (do not let butter brown).
  2. Stir in leeks, shallots, and garlic and season with salt and pepper. Gently sauté for 5–6 minutes until softened. Reduce heat to medium and pour in 2 cups milk and heavy cream (if using). Stir in potato slices and season generously with salt, pepper, and nutmeg. Potatoes should protrude just above milk; if they don’t, add more milk accordingly. Simmer, stirring frequently with a wooden spoon and checking seasoning occasionally, until milk mixture thickens, 15–20 minutes.
  3. Meanwhile, preheat oven to 425°F. Grease bottom and sides of a medium cast-iron skillet with remaining 1 tablespoon butter.
  4. Check the potato and reduced milk mixture for thickness by moving wooden spoon along bottom of pot to expose the surface; if barely any liquid fills the void, add a little more milk. Continue to cook, stirring occasionally, just until potato slices break when folded in half with your fingers, about 10 minutes. (Be careful not to overcook potatoes.)
  5. Turn off heat and spoon potato mixture into prepared cast-iron skillet, patting potato slices down as you go to fill pan completely. Cover the top evenly with Gruyère and Comté and bake in oven until gratin is bubbly and cheeses are browned and crispy, 15–20 minutes.
  6. Remove from oven and immediately top with chives so they cook a bit in the hot oil and cheeses. Let cool slightly before serving.


  • Make it more decadent: sprinkle grated Parmesan evenly into the buttered pan before filing with the potatoes for an extra layer of goodness.
  • Make it ahead of time: Do everything the same, just skip the oven portion. Refrigerate until ready.
  • Category: side dish
  • Method: bake

Keywords: potato gratin