Potatoes au Gratin (Cheesy Scalloped Potatoes)
These potatoes are rich, creamy, and incredibly cheesy! The ultimate comfort food, they are the perfect side to any holiday celebration.
Ingredients
- 2 lbs russet potatoes, washed, peeled, and ⅛" sliced (about 4–5 large potatoes)
- 1 medium yellow onion, peeled and ⅛" sliced
- 2 cloves of garlic, peeled and minced
- 2 Tbsp unsalted butter (plus more for greasing dish)
- 1 Tbsp extra virgin olive oil
- 3 Tbsp all-purpose flour
- 2 cups whole milk (or half-and-half)
- 1 cup Gruyère cheese, shredded
- 1 cup sharp white cheddar cheese, shredded
- 1 ¼ tsp kosher salt (I use Diamond Crystal)
- ½ tsp ground black pepper
For the Topping
- ½ cup Gruyère cheese, shredded
- ½ cup sharp white cheddar cheese, shredded
Instructions
- Preheat oven to 350℉.
- Peel, rinse, and slice potatoes. To prevent them from browning, place sliced potatoes in a large bowl of cold water.2 lbs russet potatoes, washed, peeled, and ⅛" sliced
- In a pot or Dutch oven, heat butter and olive oil over medium heat until foaming subsides.2 Tbsp unsalted butter1 Tbsp extra virgin olive oil
- Add in sliced onions. Cook, stirring occasionally, until onions are softened and translucent (about 10 minutes).1 medium yellow onion, peeled and ⅛" sliced
- Add in minced garlic. Cook until fragrant (about 60 seconds).2 cloves of garlic, peeled and minced
- Stir in flour and cook for 2 minutes.3 Tbsp all-purpose flour
- Meanwhile, in a saucepan, heat milk until it is scalding (i.e. just before boiling). Keep on low heat.2 cups whole milk (or half-and-half)
- While whisking, slowly add the hot milk to the pot and cook until sauce is thick and creamy (about 5 minutes).
- Off heat, add in 1 cup of each shredded cheese, salt, and pepper. Stir, and keep warm on low heat. Taste for seasonings.1 cup Gruyère cheese, shredded1 cup sharp white cheddar cheese, shredded1 ¼ tsp kosher salt½ tsp ground black pepper
- Drain and dry off sliced potatoes. In a buttered 9" by 13" oven-safe baking dish, layer sliced potatoes with cheese sauce, ⅓ at a time.
- Sprinkle the remaining ½ cup of each shredded cheese on the top of the potatoes. Cover with aluminum foil and bake in the center of the oven for 80 minutes.½ cup Gruyère cheese, shredded½ cup sharp white cheddar cheese, shredded
- Remove foil and cook, uncovered, until the potatoes are soft and the top is browned and bubbly (about 30 to 40 minutes more).
- Allow to cool for 10 minutes. Serve hot.
Notes
- Preventing the potatoes from browning: Submerge the freshly sliced potatoes in a bowl of cold water to keep them fresh until you are ready to use them. Dry them off with a clean kitchen towel (before adding them to your baking dish) so that you don’t add too much extra moisture to your sauce.
- Make it ahead: You can prepare and assemble the dish the night before and place it in the refrigerator, covered with plastic wrap, until the next day. Just be sure to allow a few extra minutes of baking time to account for the chilled ingredients.
- Baking time: Baking time largely depends on the type of potatoes you use and how thick they are cut. If you use a mandoline (or any other kitchen device that slices potatoes very thin), they will likely require less time in the oven. However, cutting them by hand typically results in thicker slices, which will require a bit more time in the oven to become soft and tender.
Nutrition
Calories: 467kcal | Carbohydrates: 37g | Protein: 20g | Fat: 27g | Saturated Fat: 15g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 7g | Trans Fat: 0.2g | Cholesterol: 73mg | Sodium: 759mg | Potassium: 832mg | Fiber: 2g | Sugar: 6g | Vitamin A: 758IU | Vitamin C: 10mg | Calcium: 568mg | Iron: 2mg