French Onion Scalloped Potatoes

If you’re a fan of rich, comforting dishes that marry the classic flavors of French onion soup with the creamy, tender texture of scalloped potatoes, then this recipe is going to be your new favorite. French Onion Scalloped Potatoes take the best parts of caramelized onions, savory broth, and melted cheese, layering them with thinly sliced potatoes to create a dish that’s both elegant and deeply satisfying. Perfect as a side for holiday dinners, family gatherings, or a cozy weeknight meal, this dish brings warmth and flavor in every bite.

Why This Recipe Is a Must-Try

French Onion Scalloped Potatoes are a delicious twist on the traditional scalloped potato recipe, incorporating the beloved flavors of French onion soup. The slow caramelization of onions adds a sweet and savory depth that elevates the dish beyond your average potato bake. Using a blend of cheeses that melt beautifully creates a luscious, golden crust that’s irresistible. This recipe is easy enough for everyday cooking but impressive enough to serve to guests. Plus, it’s made with all simple, wholesome ingredients you probably already have in your kitchen.

Ingredients

• 3 large yellow onions, thinly sliced
• 2 tablespoons olive oil
• 2 cloves garlic, minced
• 1 teaspoon fresh thyme leaves (or ½ teaspoon dried thyme)
• 4 tablespoons unsalted butter
• 4 tablespoons all-purpose flour
• 3 cups low-sodium beef broth (ensure it’s from a supplier or use vegetable broth for a lighter taste)
• 2 cups whole milk or a plant-based milk alternative
• 2 pounds Yukon Gold potatoes, peeled and thinly sliced (about 1/8-inch thick)
• 1 ½ cups shredded Gruyère cheese (or substitute with mozzarella or a mild cheddar)
• Salt and freshly ground black pepper, to taste
• Fresh parsley, chopped (for garnish)

How To Make French Onion Scalloped Potatoes

Step 1: Caramelize the Onions

Heat olive oil in a large skillet over medium heat. Add the thinly sliced onions and a pinch of salt. Cook, stirring occasionally, for 25-30 minutes until the onions are deeply golden and caramelized. Add the minced garlic and thyme in the last 5 minutes of cooking, stirring to combine. Remove from heat and set aside.

Step 2: Prepare the Creamy Sauce

In a medium saucepan, melt the butter over medium heat. Whisk in the flour and cook for about 2 minutes, stirring constantly, until the mixture is bubbly and slightly golden. Slowly whisk in the beef broth and milk, ensuring no lumps form. Continue cooking and whisking until the sauce thickens, about 5-7 minutes. Season with salt and pepper to taste. Remove from heat and stir in half of the shredded cheese.

Step 3: Assemble the Dish

Preheat your oven to 375°F (190°C). Lightly grease a 9×13-inch baking dish. Layer half of the sliced potatoes evenly in the dish. Spread half of the caramelized onions over the potatoes, then pour half of the creamy sauce on top. Repeat with the remaining potatoes, onions, and sauce.

Step 4: Bake the Potatoes

Sprinkle the remaining cheese evenly over the top of the casserole. Cover the dish with foil and bake for 45 minutes. Remove the foil and bake for an additional 20-25 minutes, or until the top is golden brown and the potatoes are tender when pierced with a fork.

Step 5: Garnish and Serve

Allow the dish to cool for 10 minutes before serving. Garnish with chopped fresh parsley for a pop of color and fresh flavor.

Expert Tips

• Slice potatoes evenly: Use a mandoline slicer or a sharp knife to ensure uniform thickness, which helps them cook evenly.
• Low and slow onion cooking: Patience is key for caramelized onions. Cooking them slowly over medium heat brings out their natural sweetness.
• Choose the right cheese: Gruyère is classic for its melt and flavor, but mozzarella or mild cheddar are great alternatives if you want a different taste or a more budget-friendly option.
• Make ahead: This dish can be assembled a day in advance. Cover and refrigerate, then bake when ready to serve (add 10 extra minutes to baking time if baking straight from the fridge).
• Rest before serving: Letting the casserole rest helps the sauce thicken and makes it easier to slice and serve.

Variations and Customizations

• Use sweet potatoes: Swap regular potatoes for sweet potatoes for a sweeter, nutrient-rich version.
• Add mushrooms: Sauté sliced mushrooms with the onions for an earthy depth of flavor.
• Spice it up: Add a pinch of smoked paprika or cayenne pepper to the sauce for a subtle kick.
• Make it vegan: Use plant-based milk, vegan butter, and dairy-free cheese alternatives.
• Herbs: Experiment with rosemary, sage, or bay leaves in the sauce for different herbal notes.

How to Store Leftovers

Store any leftover French Onion Scalloped Potatoes in an airtight container in the refrigerator for up to 3 days. To reheat, cover with foil and warm in a 350°F (175°C) oven for about 20 minutes until heated through. You can also microwave individual portions, though the oven method helps maintain the creamy texture and crispy top.

FAQ

Can I use other types of potatoes?

Yes! Yukon Gold potatoes are ideal for their creamy texture and ability to hold shape, but Russet potatoes or red potatoes can also work. Just be sure to slice them evenly to ensure consistent cooking.

Is there a way to make this recipe gluten-free?

Absolutely! Substitute the all-purpose flour with a gluten-free flour blend or cornstarch to thicken the sauce. Be sure to mix it well and adjust quantities as needed for the right consistency.

Can I prepare this dish in advance?

Yes, this casserole can be assembled a day ahead and stored covered in the refrigerator. When ready to bake, add a little extra baking time if baking straight from cold.

What can I serve with French Onion Scalloped Potatoes?

This dish pairs wonderfully with roasted or grilled meats, a fresh green salad, or steamed vegetables. It also makes a hearty vegetarian main when paired with a crisp salad or some sautéed greens.

Conclusion

French Onion Scalloped Potatoes are a luxurious, flavorful side dish that brings the beloved taste of French onion soup into a creamy, cheesy potato casserole. With caramelized onions, a rich sauce, and melty cheese, this recipe is sure to impress whether you’re making it for a special occasion or a comforting weeknight meal. It’s easy to customize and perfect for making ahead, so give it a try and enjoy a new way to elevate your potato game!