Description
Tender layers of thinly sliced potatoes baked with sweet caramelized onions and a rich, creamy Gruyère sauce, creating a golden, bubbling, and indulgent comfort side dish.
Ingredients
- 2 1/2 pounds Yukon Gold or russet potatoes, thinly sliced
- 2 tablespoons butter
- 2 large onions, thinly sliced
- 2 cloves garlic, minced
- 2 tablespoons all-purpose flour
- 2 cups whole milk
- 1 cup heavy cream
- 1 1/2 cups grated Gruyère cheese
- 1/2 teaspoon salt
- 1/2 teaspoon black pepper
- 1/4 teaspoon ground nutmeg
- Fresh thyme leaves (optional)
Instructions
- Preheat the oven to 375°F (190°C) and lightly grease a baking dish.
- In a large skillet over medium heat, melt 1 tablespoon of butter and add the sliced onions. Cook for 15–20 minutes, stirring occasionally, until soft and deeply golden. Stir in the garlic and cook for 30 seconds. Set aside.
- In the same skillet, melt the remaining butter. Whisk in the flour and cook for about 1 minute to form a roux.
- Gradually pour in the milk and heavy cream, whisking constantly to prevent lumps. Simmer until slightly thickened.
- Stir in 1 cup of the grated Gruyère cheese, salt, black pepper, and nutmeg until smooth and creamy.
- Layer half of the sliced potatoes in the prepared baking dish, followed by half of the caramelized onions. Pour a portion of the sauce over the top.
- Repeat with the remaining potatoes, onions, and sauce. Sprinkle the remaining Gruyère cheese over the top and add fresh thyme if desired.
- Cover with foil and bake for 40 minutes. Remove foil and bake an additional 20–25 minutes until golden and tender.
- Let rest for 10–15 minutes before serving to allow the sauce to set.
Notes
- Use a mandoline slicer for evenly thin potato slices to ensure consistent cooking.
- Yukon Gold potatoes provide a creamier texture, while russets offer a softer finish.
- Substitute part of the heavy cream with milk for a lighter version.
- Add grated Parmesan or a pinch of smoked paprika for additional depth of flavor.
- Store leftovers in the refrigerator for up to 4 days or freeze for up to 2 months.
Nutrition
- Serving Size: 1 serving
- Calories: 410 kcal
- Sugar: 6 g
- Sodium: 380 mg
- Fat: 24 g
- Saturated Fat: 14 g
- Unsaturated Fat: 8 g
- Trans Fat: 0 g
- Carbohydrates: 39 g
- Fiber: 3 g
- Protein: 12 g
- Cholesterol: 70 mg
