Description
Potatoes au Gratin is a rich and creamy baked potato casserole layered with slices of russet potatoes and a luscious cheese sauce made from heavy cream, cheddar, Gruyère, and Parmesan cheeses. This classic comfort dish features tender potatoes baked to golden perfection with a crispy cheesy crust, perfect as a decadent side for any meal.
Ingredients
Scale
Potatoes and Cheese
- 4 large russet potatoes, peeled and thinly sliced
- 2 cups sharp cheddar cheese, shredded
- 1 cup Gruyère cheese, shredded (optional, for extra flavor)
- 1/2 cup grated Parmesan cheese (for topping)
Sauce
- 2 cups heavy cream
- 1 cup whole milk
- 2 tablespoons unsalted butter
- 1 tablespoon all-purpose flour
- 2 cloves garlic, minced
- 1/2 teaspoon salt (or to taste)
- 1/4 teaspoon black pepper (or to taste)
- 1/4 teaspoon ground nutmeg (optional)
Garnish
- Fresh parsley, chopped (for garnish, optional)
Instructions
- Preheat the oven: Preheat your oven to 375°F (190°C). Grease a 9×13-inch baking dish with butter or non-stick spray to prevent sticking.
- Prepare the potatoes: Peel and thinly slice the russet potatoes to about 1/8-inch thickness. A mandoline slicer works best for uniform slices. Set the slices aside.
- Make the creamy sauce: In a medium saucepan, melt the unsalted butter over medium heat. Add the minced garlic and sauté for about 1 minute until fragrant but not browned.
- Form the roux: Stir in the all-purpose flour and cook for another minute, whisking constantly to create a thick paste that will thicken the sauce.
- Add cream and milk: Slowly whisk in the heavy cream and whole milk gradually, stirring constantly to avoid lumps. Continue cooking and whisking occasionally until the sauce thickens, about 4-5 minutes.
- Season and melt cheese: Remove the sauce from heat and stir in salt, black pepper, and nutmeg if using. Then add the shredded cheddar and Gruyère cheeses, stirring until smooth and fully melted into the sauce.
- Assemble the gratin: Layer half of the potato slices in the prepared baking dish evenly. Pour half of the cheese sauce over the potato layer and spread it evenly to cover.
- Layer again: Add the remaining potato slices as a second layer on top. Pour the remaining cheese sauce over the potatoes and spread it evenly to ensure all potatoes are covered.
- Bake covered: Cover the baking dish tightly with aluminum foil. Place it in the preheated oven and bake for 40 minutes to gently cook the potatoes and meld flavors.
- Add Parmesan topping: After 40 minutes, remove the foil carefully. Sprinkle the grated Parmesan cheese evenly over the top of the gratin to add a crispy, flavorful crust.
- Bake uncovered: Return the dish to the oven and bake uncovered for an additional 20-25 minutes, or until the top is golden brown and the potatoes are tender when pierced with a fork.
- Rest and garnish: Remove the gratin from the oven and let it rest for about 5 minutes to set. Sprinkle fresh chopped parsley on top if desired before serving. Serve hot as a delicious side dish.
Notes
- Use a mandoline slicer to ensure even potato slices for uniform cooking.
- Gruyère cheese is optional but adds a wonderful nutty flavor and creaminess.
- Adjust seasoning with salt and pepper to your taste preference.
- The nutmeg is optional but enhances the creamy sauce’s warmth and complexity.
- Letting the gratin rest before serving helps it set and makes slicing easier.
- For a lighter version, you can substitute half-and-half for the heavy cream.
