Description
This classic Au Gratin Potatoes recipe features thinly sliced Yukon Gold potatoes baked in a rich, creamy cheese sauce made with cheddar, gruyere, and Parmesan. Layered with onions and garlic, this decadent side dish is perfect for holiday dinners or comforting family meals.
Ingredients
Scale
Potatoes and Onions
- 3 lbs Yukon Gold potatoes (thinly sliced, about 12 potatoes)
- ½ yellow onion (thinly sliced)
Sauce
- 4 tbsp unsalted butter (½ stick, plus more for greasing the pan)
- 2 cloves garlic (minced)
- ¼ cup all-purpose flour
- 1½ cups whole milk
- 1 tsp kosher salt
- ½ tsp ground black pepper
Cheese
- 1 cup freshly shredded cheddar cheese
- 1½ cups freshly shredded gruyere cheese (divided)
- ½ cup freshly grated Parmesan cheese
Instructions
- Preheat and Prepare Pan: Preheat your oven to 350°F and generously grease a 9×13-inch baking pan with butter to prevent sticking.
- Layer Potatoes and Onions: Arrange the thinly sliced Yukon Gold potatoes and yellow onions in alternating layers in the prepared baking dish; set aside while you prepare the sauce.
- Make the Cheese Sauce: In a medium saucepan, melt 4 tablespoons of unsalted butter over medium heat. Add the minced garlic and cook until fragrant, about 1 minute. Sprinkle the flour over the butter and garlic mixture and whisk continuously until smooth and lightly golden, about 1 minute.
- Add Milk and Simmer: Slowly whisk in the whole milk, ensuring that you break up any lumps. Bring the sauce to a gentle simmer while whisking continuously until it thickens slightly.
- Incorporate Seasoning and Cheese: Remove the sauce from heat. Whisk in kosher salt, ground black pepper, shredded cheddar cheese, and ¾ cup of the shredded gruyere cheese until melted and smooth.
- Combine Sauce with Potatoes: Pour the cheese sauce evenly over the layered potatoes and onions in the baking dish.
- Bake Covered: Cover the baking dish tightly with aluminum foil and bake for 60 minutes or until the potatoes are tender when pierced with a knife.
- Add Remaining Cheese: Remove the foil and sprinkle the remaining ¾ cup of gruyere cheese along with the grated Parmesan evenly over the top.
- Bake Uncovered: Return the dish to the oven and bake uncovered for an additional 15-20 minutes, until the cheese is melted and bubbly.
- Optional Broil for Browning: For a beautifully browned and crispy cheese topping, broil the potatoes for 1-2 minutes, watching carefully to avoid burning.
- Garnish and Serve: Remove from the oven, garnish with fresh herbs if desired, and serve warm as a delicious side dish.
Notes
- Use Yukon Gold potatoes for their creamy texture and buttery flavor, but russet potatoes can be substituted if needed.
- Ensure potatoes are sliced thinly and evenly to help them cook through in the allotted time.
- If you want a richer sauce, substitute part of the whole milk with heavy cream.
- For a sharper taste, add more cheddar or use sharp white cheddar instead of mild.
- Covering the dish with foil during the initial bake prevents the top from browning too early and helps cook the potatoes evenly.
- Broiling at the end is optional but gives the gratin a beautifully golden and crispy cheese crust.
- Let the dish rest for 5-10 minutes after baking to set slightly before serving.
Nutrition
- Serving Size: 1 serving
- Calories: 413 kcal
- Sugar: 4 g
- Sodium: 698 mg
- Fat: 22 g
- Saturated Fat: 13 g
- Unsaturated Fat: 7 g
- Trans Fat: 0.2 g
- Carbohydrates: 37 g
- Fiber: 4 g
- Protein: 18 g
- Cholesterol: 67 mg
