Description
A rich and cozy fusion of French onion soup and classic scalloped potatoes, this dish layers caramelized onions and creamy cheese sauce between tender potato slices for a comforting, crowd-pleasing bake.
Ingredients
Scale
- 3 large yellow onions, thinly sliced
- 4 medium russet potatoes, peeled and thinly sliced
- 4 tablespoons butter
- 3 tablespoons all-purpose flour
- 1 cup beef broth
- 1 ½ cups heavy cream
- 2 cups shredded Gruyère cheese
- 1 cup shredded mozzarella cheese
- 1 teaspoon salt
- ½ teaspoon black pepper
- 1 teaspoon chopped fresh thyme
Instructions
- Preheat your oven to 375°F (190°C). Lightly grease a 9×13-inch baking dish.
- In a large skillet, melt 2 tablespoons of butter over medium heat. Add the onions and cook, stirring occasionally, until caramelized (about 20 to 25 minutes). Set aside.
- In a saucepan, melt the remaining butter. Whisk in flour and cook for 1 minute. Slowly add beef broth and cream, whisking constantly until thickened.
- Stir in Gruyère and mozzarella cheeses (reserving a portion for topping), salt, pepper, and thyme until the sauce is smooth.
- Spread a spoonful of sauce on the bottom of the baking dish. Layer half the potatoes, half the onions, and half the cheese sauce. Repeat with remaining layers and top with reserved cheese.
- Cover with foil and bake for 45 minutes. Uncover and bake an additional 15 to 20 minutes until golden and bubbly.
- Let rest for 10 minutes before serving to allow the sauce to set.
Notes
- Use a mandoline slicer for even potato slices.
- Caramelize onions low and slow for the best flavor.
- Freshly shredded cheese melts better than pre-packaged.
- Dish can be assembled ahead and baked later.
Nutrition
- Serving Size: 1 portion
- Calories: 380
- Sugar: 5g
- Sodium: 520mg
- Fat: 26g
- Saturated Fat: 15g
- Unsaturated Fat: 9g
- Trans Fat: 0g
- Carbohydrates: 28g
- Fiber: 3g
- Protein: 10g
- Cholesterol: 75mg
Keywords: french onion potatoes, scalloped potatoes, cheesy potatoes, potato casserole, holiday side dish