Description
This classic Au Gratin Potatoes recipe features thinly sliced Russet potatoes baked in a rich and creamy cheese sauce made with Parmigiano-Reggiano and cheddar cheeses. Perfectly baked to a golden brown top with a luscious, cheesy interior, this comforting dish is a great side for any meal.
Ingredients
Scale
For the Dish
- Butter, for greasing the baking dish
For the Potatoes and Sauce
- 2½ pounds Russet potatoes (3 to 4 large), peeled and sliced very thin
- 1½ teaspoons salt
- ¼ teaspoon freshly ground black pepper
- 1 cup (4 oz) finely grated Parmigiano-Reggiano cheese
- 2¼ cups heavy cream
- 1 cup shredded cheddar cheese
- 1 medium onion, finely chopped
- 2 cloves garlic, minced
- 2 tablespoons all-purpose flour
- 1 cup milk
For Garnish (Optional)
- Fresh thyme or chopped parsley
Instructions
- Preheat and Prepare: Set your oven temperature to 350°F (175°C). Grease a 2-quart baking dish generously with butter to prevent sticking.
- Cook Onions and Garlic: Heat butter in a large saucepan over medium-high heat. Add the chopped onions and cook for 5 to 6 minutes until tender and translucent. Add minced garlic and cook for an additional 1 minute, stirring to avoid burning.
- Create the Cream Sauce: Stir in the flour until fully combined with the onion mixture. Let it cook for about 1 to 2 minutes to eliminate the raw flour taste. Gradually whisk in the heavy cream and milk, stirring constantly to prevent lumps. Bring the mixture slowly to a boil, then reduce heat to low and simmer until the sauce thickens slightly.
- Add Cheese and Seasoning: Add salt, freshly ground black pepper, shredded cheddar cheese, and the grated Parmigiano-Reggiano to the sauce. Stir continuously until the cheeses melt completely and the sauce is smooth.
- Combine Potatoes with Sauce: Add the thinly sliced potatoes to the cream and cheese sauce, mixing gently but thoroughly to ensure all slices are coated evenly.
- Assemble and Bake: Transfer the potato mixture into the prepared baking dish. Sprinkle the remaining Parmesan cheese evenly over the top. Cover the dish with aluminum foil.
- Initial Bake: Bake in the preheated oven for approximately 1 hour, or until the potatoes are tender when pierced with a fork. Baking time depends on the thickness of the slices.
- Bake Uncovered for Browning: Remove the foil after the initial 40 minutes or once the top begins to lightly brown. Continue baking uncovered for about 20 minutes or until the top is golden and bubbly.
- Rest and Serve: Allow the gratin to rest for 5 minutes after removing it from the oven to settle the flavors and make serving easier. Garnish with fresh thyme or chopped parsley if desired and serve warm.
Notes
- For best results, slice potatoes very thinly using a mandoline for even cooking.
- Adjust baking time according to the thickness of potato slices to avoid undercooked or overly soft potatoes.
- Heavy cream and milk combination creates a creamy texture; avoid using low-fat milk for best richness.
- This dish can be prepared ahead of time; refrigerate before baking and add a few extra minutes to the cooking time if baking from chilled.
- Leftovers can be refrigerated and reheated in the oven to maintain crispness.
- Prep Time: 20 minutes
- Cook Time: 1 hour 20 minutes
- Category: Side Dish
- Method: Baking
- Cuisine: French
Keywords: Au Gratin Potatoes, Potato Gratin, Cheesy Potatoes, Baked Potatoes, Side Dish, Comfort Food
