Description
A comforting casserole that transforms French onion soup flavors into a hearty potato dish with caramelized onions and melted Gruyère cheese.
Ingredients
Scale
- 3 pounds Yukon Gold potatoes, peeled and sliced 1/8-inch thick
- 4 large yellow onions (about 2 pounds), thinly sliced
- 4 tablespoons unsalted butter
- 2 tablespoons olive oil
- 1 teaspoon salt, plus more for seasoning
- 1/2 teaspoon black pepper
- 2 tablespoons fresh thyme leaves
- 3 cloves garlic, minced
- 1/4 cup dry white wine
- 2 cups beef broth
- 1 cup heavy cream
- 8 ounces Gruyère cheese, grated
- 1/2 cup grated Parmesan cheese
- 2 tablespoons fresh chives, chopped
Instructions
- 1. Preheat oven to 375°F and grease a 9×13-inch baking dish.
- 2. Heat butter and oil in large skillet over medium-low heat. Add onions, salt, and pepper. Cook 45-60 minutes until deeply caramelized.
- 3. Add garlic and thyme to onions. Cook 2 minutes. Add wine and reduce by half.
- 4. Warm beef broth and cream in saucepan over low heat.
- 5. Slice potatoes into uniform 1/8-inch rounds.
- 6. Layer half the potatoes in baking dish. Season and add half the onions.
- 7. Sprinkle half the Gruyère, then repeat layers.
- 8. Pour warm broth mixture over casserole.
- 9. Cover with foil and bake 1 hour. Remove foil and bake 30-40 minutes until golden.
- 10. Add Parmesan in last 10 minutes. Rest 15 minutes before serving.
- 11. Garnish with fresh chives.
Notes
Store covered in refrigerator up to 4 days. Can be assembled ahead and refrigerated before baking. Reheat gently to prevent cream from separating.
- Prep Time: 30 minutes
- Cook Time: 2 hours
- Category: Side Dish
- Method: Baking
- Cuisine: American
Nutrition
- Serving Size: 1 serving
- Calories: 385
- Sugar: 8g
- Sodium: 680mg
- Fat: 22g
- Carbohydrates: 38g
- Fiber: 4g
- Protein: 12g