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Potato Gratin with Warmed Cream and Gruyère — Predictable Timing for Busy Cooks Pinterest recipe pin

Reliable Potato Gratin with Warmed Cream and Gruyère

A dependable oven-baked potato gratin with thin, uniform slices, a quick stovetop cream infusion, and a golden Gruyère top for creamy, sliceable results.
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Prep Time 25 minutes
Cook Time 1 hour 5 minutes
Total Time 1 hour 40 minutes
Servings: 8 servings
Calories: 380
Ingredients Equipment Method Notes

Ingredients
  

  • 3 pounds Yukon Gold potatoes trimmed (about 6 medium), thinly sliced 1/8 inch
  • 2 cups half-and-half or 1 cup half-and-half + 1 cup whole milk
  • 2 cloves garlic smashed
  • 1 teaspoon fresh thyme leaves or 1/2 teaspoon dried
  • 1 teaspoon Dijon mustard
  • 1/2 teaspoon kosher salt plus extra to taste
  • 1/2 teaspoon freshly ground black pepper
  • 1 1/2 cups grated Gruyère cheese divided
  • 1/4 cup grated Parmesan cheese
  • 2 tablespoons unsalted butter for greasing the dish
Optional additions
  • 1 large onion thinly sliced and caramelized (optional)
  • 1 tablespoon chopped fresh rosemary optional

Equipment

  • 1 9×13-inch baking dish
  • 1 Mandoline or sharp chef's knife
  • 1 Medium saucepan
  • 1 Box grater

Method
 

Prep and preheat
  1. Preheat the oven to 375°F and butter a 9×13-inch baking dish; set aside. Trim potatoes and slice them very thin (about 1/8 inch) using a mandoline or sharp knife, placing slices in cold water to hold color, then drain and pat dry before assembling.
Infuse the cream
  1. In a medium saucepan over medium heat, combine half-and-half, smashed garlic, thyme, Dijon mustard, 1/2 teaspoon kosher salt, and black pepper and bring to a gentle simmer (small bubbles at the edge). Simmer gently for 3–4 minutes to concentrate flavor, then remove from heat and let sit 5 minutes to finish infusing.
Assemble
  1. Arrange a single overlapping layer of potato slices across the bottom of the prepared dish, season lightly with pepper and a pinch of salt, and sprinkle 1/3 of the Gruyère (about 1/2 cup) over the layer. Repeat two more times until the dish is nearly full, finishing with the remaining Gruyère and the Parmesan on top.
Bake and finish
  1. Carefully pour the warm cream mixture evenly over the potatoes so it comes about three-quarters up the sides. Cover with foil and bake at 375°F for 35 minutes, then remove the foil and bake another 25–30 minutes until the top is golden and a knife slides through the center slices with little resistance. Tent with foil if browning too fast.
Rest and serve
  1. Remove from the oven and let the gratin rest 10–15 minutes to allow the sauce to set. Cut into squares and serve warm.

Notes

Use a mandoline for even 1/8-inch slices; if using Russets add 2–4 tablespoons extra cream. Warm the cream before pouring to avoid a thin sauce, and rest the finished gratin 10–15 minutes for cleaner slices. If making ahead, assemble and refrigerate up to 24 hours before baking; add 5–10 minutes to bake time if chilled.