Ingredients
- Russet Potatoes: (3 pounds) – The high starch content of Russets makes them ideal for au gratin, holding their shape while becoming tender and creamy.
- Yellow Onion: (1 medium) – Adds a subtle savory sweetness and depth of flavor to the creamy sauce.
- Garlic: (3 cloves) – Fresh garlic provides a pungent aroma and enhances the overall savory notes of the dish.
- Heavy Cream: (2 cups) – The foundation of the rich and decadent cream sauce, providing unparalleled creaminess.
- Milk: (1 cup) – Balances the richness of the heavy cream, creating a perfectly textured sauce.
- Gruyere Cheese: (8 ounces) – A nutty and slightly sweet cheese that melts beautifully and provides a classic au gratin flavor.
- Sharp Cheddar Cheese: (4 ounces) – Adds a tangy sharpness and vibrant cheesy flavor that complements the Gruyere.
- Unsalted Butter: (4 tablespoons) – Used to create a roux that thickens the sauce and adds richness and flavor.
- All-Purpose Flour: (3 tablespoons) – Essential for creating a stable roux that thickens the cream sauce.
- Fresh Thyme: (1 tablespoon, chopped) – Provides a delicate herbal aroma and flavor that complements the potatoes and cheese.
- Nutmeg: (1/4 teaspoon, ground) – A warm spice that adds a subtle depth and complexity to the creamy sauce.
- Salt: (To taste) – Enhances the flavors of all the ingredients and seasons the dish perfectly.
- Black Pepper: (Freshly ground, to taste) – Adds a touch of spice and complements the richness of the cheese and cream.
Instructions
- Prepare the Potatoes and Onion: Begin by preheating your oven to 375°F (190°C). While the oven is heating, thoroughly wash and peel the russet potatoes. Using a mandoline or a sharp knife, thinly slice the potatoes to about 1/8 inch thickness. Uniformly thin slices are crucial for even cooking and a creamy texture. Peel and thinly slice the yellow onion as well. Set both aside.
- Sauté the Aromatics: In a large, oven-safe skillet (cast iron works wonderfully) or a large saucepan over medium heat, melt 2 tablespoons of unsalted butter. Add the sliced onion and sauté until softened and translucent, about 5-7 minutes. Add the minced garlic and cook for another minute until fragrant, being careful not to burn the garlic. Remove the onion and garlic mixture from the skillet and set aside.
- Create the Roux: In the same skillet, melt the remaining 2 tablespoons of butter over medium heat. Once melted, whisk in the all-purpose flour and cook for about 1-2 minutes, stirring constantly, until the roux is smooth and pale golden. This step is crucial for thickening the sauce and removing the raw flour taste.
- Make the Cream Sauce: Gradually whisk in the heavy cream and milk to the roux, ensuring there are no lumps. Continue whisking until the sauce is smooth. Bring the sauce to a gentle simmer over medium-low heat, stirring frequently to prevent scorching. Reduce the heat to low and simmer for about 5-7 minutes, or until the sauce has slightly thickened.
- Infuse with Flavor: Remove the skillet from the heat. Stir in the chopped fresh thyme, ground nutmeg, salt, and freshly ground black pepper to taste. Adjust seasonings as needed. Add the sautéed onion and garlic mixture back into the cream sauce and stir to combine.
- Assemble the Au Gratin: Add about half of the shredded Gruyere and half of the shredded sharp cheddar cheese to the cream sauce. Stir until the cheese is melted and the sauce is smooth and cheesy. This creates a luscious cheese sauce that will coat the potatoes beautifully.
- Layer the Potatoes: Begin layering the sliced potatoes in the cheese sauce, overlapping them slightly in a circular pattern to cover the bottom of the skillet. Pour a generous amount of the cheese sauce over the potato layer, ensuring all potatoes are coated. Continue layering the potatoes and cheese sauce, repeating until all potatoes and sauce are used, ending with a layer of cheese sauce.
- Top with Cheese: Sprinkle the remaining shredded Gruyere and sharp cheddar cheese evenly over the top layer of potatoes and cheese sauce. This cheesy topping will create a golden brown and bubbly crust during baking.
- Bake to Perfection: Place the skillet in the preheated oven and bake for 50-60 minutes, or until the potatoes are tender when pierced with a fork and the top is golden brown and bubbly. If the top begins to brown too quickly, you can loosely tent the skillet with aluminum foil for the last 15-20 minutes of baking.
- Rest and Serve: Once baked, remove the skillet from the oven and let it rest for about 10-15 minutes before serving. This resting time allows the sauce to thicken slightly and the flavors to meld together beautifully. Serve hot and enjoy the creamy, cheesy goodness of your homemade Au Gratin Potatoes!
Nutrition
- Serving Size: one normal portion
- Calories: 400
- Fat: 30g