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Cheesy potato gratin casserole easy recipe
Milica

Cheesy Potato Gratin Casserole

This cheesy potato gratin casserole is the epitome of comfort food, combining thinly sliced potatoes with a luscious cream sauce and a golden, cheesy crust.
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Prep Time 20 minutes
Cook Time 1 hour
Total Time 1 hour 20 minutes
Servings: 6 servings
Course: Side Dish
Cuisine: French
Calories: 400
Ingredients Method Notes

Ingredients
  

  • Ingredients
For this cheesy potato gratin casserole, you’ll need simple ingredients that pack maximum flavor:
  • 4 large russet potatoes peeled and thinly sliced (about ⅛-inch thick)
  • 1 ½ cups heavy cream substitute with cashew cream for a dairy-free version
  • 1 cup whole milk or unsweetened almond milk
  • 2 garlic cloves minced
  • 1 teaspoon salt
  • ½ teaspoon freshly ground black pepper
  • 1 teaspoon smoked paprika optional, for added depth
  • 1 ½ cups shredded Gruyère cheese or sharp cheddar for a twist
  • ½ cup freshly grated Parmesan cheese
  • 2 tablespoons unsalted butter cut into small cubes
  • 1 teaspoon fresh thyme leaves optional, for garnish

Method
 

  1. Set your oven to 375°F (190°C). Grease a 9×13-inch casserole dish generously with butter or cooking spray to ensure easy serving later.
  2. In a medium saucepan, combine the heavy cream, milk, minced garlic, salt, black pepper, and smoked paprika. Heat the mixture over medium heat, whisking occasionally to prevent the milk from scalding.
  3. Using a mandoline slicer or sharp knife, slice the potatoes into even, thin rounds. 
  4. Arrange half of the potato slices in overlapping layers at the bottom of your prepared casserole dish. 
  5. Sprinkle half of the shredded Gruyère and Parmesan cheese evenly over the potato layer. Pour half of the warm cream mixture on top, ensuring it seeps into the layers.
  6. Layer the remaining potatoes in the same manner, followed by the rest of the cheese and cream mixture. 
  7. Scatter small cubes of butter across the top layer. This step helps achieve a beautifully golden and crisp crust.
  8. Cover the casserole tightly with aluminum foil and bake in the preheated oven for 45 minutes.
  9. After 45 minutes, remove the foil and bake for an additional 15 minutes. The top should turn golden brown, with bubbling cheese along the edges.

Notes

  • Use Starchy Potatoes: Russet or Yukon Gold potatoes work best because they absorb the cream well and maintain their structure.
  • Cheese Alternatives: Gruyère is classic for its nutty flavor, but feel free to mix in sharp cheddar, Fontina, or even Monterey Jack for variety.
  • Make Ahead: Assemble the dish up to a day in advance, cover it tightly, and refrigerate. When ready to bake, let it come to room temperature first to ensure even cooking.