A comforting and indulgent dish that layers creamy potatoes with sweet caramelized onions and gooey cheese, perfect for any occasion.
French Onion Potato Bake is the perfect comfort food that fuses the rich flavors of French onion soup with the hearty satisfaction of a classic potato gratin. Each bite delivers velvety layers of thinly sliced potatoes infused with the sweetness of deeply caramelized onions, all brought together by a luxurious cream sauce and a blend of gooey melted cheeses. This dish is a standout for holiday tables, special dinners, or just whenever you’re craving something warm and indulgent.
Ingredients
For the Caramelized Onions:
2 large yellow onions, thinly sliced
2 tablespoons butter
1 tablespoon olive oil
1 teaspoon salt
½ teaspoon black pepper
1 teaspoon sugar (optional)
½ teaspoon garlic powder
½ teaspoon dried thyme (or 1 teaspoon fresh)
½ cup beef broth (or vegetable broth for vegetarian)
For the Potato Bake:
4 large Yukon Gold potatoes, sliced ¼-inch thick
1 tablespoon butter (for greasing dish)
1 cup shredded Gruyère cheese (or Swiss, cheddar, or mozzarella)
½ cup grated Parmesan cheese
1 cup heavy cream or whole milk
½ teaspoon salt
¼ teaspoon black pepper
1 teaspoon fresh thyme leaves
For Garnish:
Fresh thyme sprigs
Extra Parmesan cheese
Crispy fried onions (optional)
Directions
- Prepare the Caramelized Onions
In a large skillet, melt the butter and olive oil over medium heat. Add the sliced onions, salt, black pepper, and sugar (if using). Cook slowly, stirring occasionally, for about 20–25 minutes until the onions become soft, golden, and deeply sweet. Stir in garlic powder, thyme, and broth. Let the mixture simmer until the liquid is nearly gone. Set aside. - Preheat the Oven
Set your oven to 375°F (190°C). Grease your baking dish with the tablespoon of butter to prevent sticking. - Layer the Potatoes and Onions
Arrange half of the potato slices in a layer on the bottom of the baking dish. Sprinkle with half of the Gruyère cheese, half of the Parmesan, and half of the caramelized onions. Repeat with a second layer of potatoes, cheese, and onions. - Mix and Pour the Cream Sauce
In a bowl, combine heavy cream (or whole milk), salt, pepper, and fresh thyme. Pour this evenly over the layered potatoes and onions. - Bake the Dish
Cover the dish with aluminum foil and bake for 45 minutes. Then remove the foil and continue baking for another 15–20 minutes, or until the top is golden and bubbling and the potatoes are fork-tender. - Garnish and Serve
Let the dish cool slightly before garnishing with fresh thyme, extra Parmesan, and crispy fried onions if desired. Serve warm.
Nutritional Information
Prep Time: 15 minutes
Cooking Time: 1 hour
Total Time: 1 hour 15 minutes
Approximately 350 kcal per serving
Servings: 6
The Heart of the Dish: Caramelized Onions
Caramelized onions are the soul of this bake. They offer a slow sweetness that contrasts the richness of the cheese and cream, turning a simple potato dish into something deeply flavorful. The process of caramelization transforms the sharpness of raw onions into a mellow, almost jam-like quality. Adding broth at the end enhances the depth, making every bite taste like it simmered for hours.
Potatoes: The Pillowy Base
Yukon Golds are ideal for their natural creaminess and ability to hold their shape during baking. Their thin skins mean no peeling is required unless you prefer it. When sliced evenly at a quarter-inch thickness, they absorb flavor perfectly while softening just enough to be fork-tender but not mushy. Soaking slices briefly in water can remove excess starch, preventing clumping.
Cheese Choices and Melting Tips
Gruyère cheese is traditionally used in French onion soup, making it the natural choice for this bake. It melts smoothly, adds a subtle nutty flavor, and browns beautifully. Parmesan provides a salty, crisp counterpoint. Don’t hesitate to experiment—cheddar brings sharpness, mozzarella boosts stretchiness, and Swiss cheese adds a mellow tone. Mix and match depending on your pantry and taste preferences.
The Cream Layer That Brings It All Together
Heavy cream adds richness while carrying flavor into every crevice between the potatoes. If you’re looking for a slightly lighter version, whole milk works well too. Seasoning the cream is essential—this is your opportunity to ensure every bite is well flavored. A hint of fresh thyme brings balance to the richness, making the dish aromatic and inviting.
Serving Suggestions
This bake stands strong as a side or main course. It pairs well with roast beef, grilled chicken, or pan-seared salmon. For a vegetarian meal, add a big green salad with vinaigrette to cut through the richness. A glass of dry white wine or sparkling water with lemon completes the plate. Leftovers are equally delicious the next day, making it a wonderful make-ahead option for guests or family meals.
Storage and Reheating Tips
Store leftovers in an airtight container in the refrigerator for up to 3 days. To reheat, bake at 350°F (175°C) covered with foil until heated through—usually 20–30 minutes. You can microwave individual portions, but oven reheating retains the texture better. This dish also freezes well: portion it, wrap tightly, and store in a freezer-safe container. Thaw overnight in the refrigerator before baking.
Optional Add-ins and Variations
This dish is easy to customize:
- Add cooked, crumbled bacon or pancetta between the layers for a smoky note.
- Try layering in sautéed mushrooms for an earthy depth.
- Add fresh rosemary, sage, or even caramelized leeks.
- Spice it up with red pepper flakes or a dash of smoked paprika.
- Make it vegetarian by using vegetable broth and sticking to cheese-only layers.
Making It Ahead
French Onion Potato Bake is an excellent candidate for preparing in advance. Assemble the dish and refrigerate it up to 24 hours before baking. Let it come to room temperature before putting it in the oven, or add 10–15 minutes to the covered baking time if baking directly from the fridge.
Texture Tips
For extra crispiness, uncover the dish for the last 15–20 minutes and place it under the broiler for 2–3 minutes to develop a golden, bubbly crust. Let it sit for 10 minutes before serving so the cream sets and the layers hold together better when sliced.
Why This Dish Works
This recipe is a balance of sweet, savory, creamy, and crispy. The layering technique ensures you get a little of everything in every bite. It’s hearty without being heavy, and luxurious without requiring hard-to-find ingredients. It’s a crowd-pleaser, a comfort food upgrade, and a showstopper when presented straight from the oven.