Description
Classic Au Gratin Potatoes baked in a creamy, cheesy sauce featuring Yukon Gold potatoes layered with onions and three types of cheese for a rich and comforting side dish, perfect for holiday dinners or any special meal.
Ingredients
Scale
Potatoes and Vegetables
- 3 lbs Yukon Gold potatoes (thinly sliced, about 12 potatoes)
- ½ yellow onion (thinly sliced)
Sauce and Cheese
- 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
- 1 cup freshly shredded cheddar cheese
- 1½ cups freshly shredded gruyere cheese (divided)
- ½ cup freshly grated Parmesan cheese
Instructions
- Preheat and Prepare: Preheat your oven to 350°F and generously butter a 9×13-inch baking pan to prevent sticking and add flavor.
- Layer Potatoes and Onions: Arrange the thinly sliced Yukon Gold potatoes and yellow onions in layers inside the prepared baking dish, ensuring they are evenly distributed.
- Make the Roux: In a medium saucepan over medium heat, melt 4 tablespoons of unsalted butter. Add minced garlic and cook until fragrant, about 1 minute, stirring frequently to avoid burning.
- Add Flour: Sprinkle the all-purpose flour over the butter and garlic mixture. Whisk continuously until the flour is smooth and golden, about 1 minute, creating a roux that will thicken the sauce.
- Incorporate Milk: Slowly pour in the whole milk while whisking vigorously to prevent lumps and achieve a smooth sauce. Bring the mixture to a gentle simmer.
- Add Seasoning and Cheese: Remove the sauce from heat and whisk in kosher salt, ground black pepper, shredded cheddar cheese, and ¾ cup of shredded gruyere cheese until fully melted and smooth.
- Combine and Bake: Pour the cheese sauce evenly over the layered potatoes and onions in the baking dish. Cover the dish tightly with foil and bake in the preheated oven for 60 minutes, or until the potatoes are tender when pierced with a knife.
- Add Toppings and Finish Baking: Remove the foil, sprinkle the remaining ¾ cup gruyere and the grated Parmesan cheese evenly over the top. Return the dish to the oven and bake uncovered for an additional 20 minutes until the cheese is melted and bubbly.
- Optional Broil: For a golden brown cheese crust, broil the dish for 1-2 minutes, watching carefully to prevent burning.
- Garnish and Serve: Garnish with fresh herbs of your choice (such as parsley or thyme) and serve hot as a decadent side dish.
Notes
- Use Yukon Gold potatoes for their creamy texture and buttery flavor; russet potatoes can make the dish less creamy.
- Ensure the potatoes are sliced thinly and evenly to allow even cooking.
- If you prefer a lighter dish, substitute whole milk with 2% milk, but the texture may be slightly less rich.
- Gruyere cheese provides a nutty flavor; you can substitute with Swiss cheese if unavailable.
- To save time, prepare the sauce ahead and assemble just before baking.
- Use fresh herbs like thyme or rosemary for an aromatic garnish that complements the cheese.
- If you don’t have kosher salt, use sea salt but adjust the quantity slightly to taste.
- For a gluten-free version, substitute all-purpose flour with a gluten-free flour or cornstarch thickener.
- Leftovers can be refrigerated and reheated in the oven to retain crispness.
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
