Ingredients

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)

Instructions

Step 1: Preheat the oven to 375°F (190°C). Generously grease a 9×13-inch casserole dish with butter or cooking spray to prevent sticking.

Step 2: In a medium saucepan, combine the heavy cream, milk, minced garlic, salt, black pepper, and smoked paprika. Warm the mixture over medium heat, whisking occasionally to avoid scalding.

Step 3: Slice the potatoes into thin, even rounds using a mandoline slicer or a sharp knife.

Step 4: Arrange half of the potato slices in overlapping layers at the bottom of the prepared casserole dish.

Step 5: Sprinkle half of the Gruyère and Parmesan cheese evenly over the potatoes, then pour half of the warm cream mixture on top, allowing it to seep into the layers.

Step 6: Repeat the layering with the remaining potatoes, cheese, and cream mixture.

Step 7: Dot the top layer with small cubes of butter to encourage a golden, crisp crust.

Step 8: Cover the casserole tightly with aluminum foil and bake for 45 minutes.

Step 9: Remove the foil and continue baking for an additional 15 minutes until the top is golden brown and bubbly.

Tips & Variations

For a dairy-free version, substitute heavy cream with cashew cream and use unsweetened almond milk instead of whole milk.

Try adding fresh herbs like rosemary or thyme between layers for extra flavor.

Use sharp cheddar cheese for a tangier, richer taste instead of Gruyère.

To save time, slice potatoes ahead and rinse them in cold water to remove excess starch, drying well before layering.

FAQs

Can I prepare the gratin ahead of time?

Yes, you can assemble the gratin a few hours ahead and keep it covered in the refrigerator. Bake it just before serving, adding a few extra minutes if baking from cold.

What type of potatoes works best?

Russet potatoes are ideal due to their starchy texture, which creates a creamy interior. Waxy potatoes can be used but may result in a firmer texture.