Get ready to fall in love with your new favorite side dish. This French Onion Potato Bake combines the rich, savory depth of classic French onion soup with the comforting, cheesy goodness of a potato gratin. It’s a decadent, crowd-pleasing casserole that’s perfect for holidays, family dinners, or any time you crave something truly special.
We’ve crafted this recipe to be straightforward, ensuring you get those perfectly jammy, caramelized onions and tender, flavorful potatoes every single time. It’s the ultimate comfort food experience.
Why This French Onion Potato Bake Recipe is a Must-Try
This isn’t just another potato dish; it’s an event. The magic starts with deeply caramelized onions, simmered with beef broth and thyme, which creates an incredibly rich flavor base. This savory mixture is then layered with thinly sliced potatoes and a generous amount of Gruyère cheese, then baked until bubbly and golden brown.
It’s a showstopper that delivers on both flavor and presentation. Plus, it’s a fantastic way to elevate a simple weeknight dinner or to impress guests at your next gathering.
The Key Ingredients for an Unforgettable Potato Bake
The beauty of this French Onion Potato Bake lies in its simple, high-quality ingredients. Each component plays a crucial role in building the signature flavor profile.
For the Potatoes
- Potatoes: We recommend using Yukon Gold or Russet potatoes. They hold their shape well and become wonderfully creamy when baked.
- Heavy Cream: This creates the luscious, rich sauce that envelops the potatoes.
- Gruyère Cheese: The star of the show! Its nutty, slightly sweet flavor is the classic choice for French onion soup and works beautifully here.
For the French Onion Flavor
- Yellow Onions: The foundation of our flavor. Sliced thin and caramelized low and slow for maximum sweetness.
- Butter & Olive Oil: A combination for caramelizing the onions. Butter adds flavor, while oil prevents the butter from browning too quickly.
- Garlic: Adds a layer of aromatic depth.
- Beef Broth: Provides the savory, umami-rich backbone of the sauce.
- Dry White Wine: A splash of Sauvignon Blanc or Pinot Grigio deglazes the pan and adds complexity. This is optional but highly recommended.
- Fresh Thyme: Its earthy notes are a classic pairing with caramelized onions.
Step-by-Step Guide to the Perfect French Onion Potato Bake
Follow these steps closely, and you’ll be rewarded with the most delicious potato bake you’ve ever had. Patience is key, especially when caramelizing the onions!
Step 1: Caramelize the Onions to Perfection
This is the most important step for developing a deep, rich flavor. Do not rush it! In a large skillet, melt butter with olive oil over medium-low heat. Add the sliced onions and a pinch of salt. Cook slowly, stirring occasionally, for 30-40 minutes, until the onions are soft, jammy, and a deep golden brown. Add the minced garlic and thyme, cooking for another minute until fragrant. If using, pour in the white wine to deglaze, scraping up any browned bits. Simmer until the wine has mostly evaporated.
Step 2: Prepare the Potatoes
While the onions are caramelizing, preheat your oven to 400°F (200°C) and butter a 9×13 inch baking dish. Wash and peel your potatoes. Using a mandoline slicer or a sharp knife, slice the potatoes into 1/8-inch thick rounds. Uniform thickness is key to even cooking.
Step 3: Create the Creamy Sauce
In a large bowl, whisk together the heavy cream, beef broth, salt, and pepper. This simple mixture will become a rich, bubbly sauce in the oven, absorbing all the incredible flavors from the other ingredients.
Step 4: Assemble and Bake the Casserole
Arrange one-third of the potato slices in an overlapping layer in the prepared baking dish. Top with half of the caramelized onions and one-third of the shredded Gruyère cheese. Repeat the layers, finishing with a final layer of potatoes. Pour the cream and broth mixture evenly over the top. Finish with the remaining Gruyère cheese. Bake, uncovered, for 50-60 minutes, or until the potatoes are tender and the top is golden brown and bubbly. Let it rest for 10 minutes before serving. For a richer side, check out this creamy mashed potatoes recipe (coming soon).
Pro Tips for the Best French Onion Potatoes
- Slice Potatoes Evenly: A mandoline is your best friend for this recipe. Even slices mean even cooking.
- Don’t Crowd the Onions: Use a large skillet to caramelize your onions so they have plenty of room to cook down without steaming.
- Rest Before Serving: Letting the bake rest for at least 10 minutes allows the sauce to set up, making it easier to serve. If you love cheesy casseroles, you might also enjoy this Southern Spaghetti Bake.
Delicious Variations to Try
While the classic recipe is divine, feel free to get creative! Try adding crispy bacon bits between the layers, or swap the Gruyère for a mix of white cheddar and Parmesan. For a heartier main course, you could layer in some shredded rotisserie chicken. It’s a versatile base, much like this French Onion Pot Roast.
What to Serve with Your Potato Bake
This French Onion Potato Bake is a fantastic side dish for roasted chicken, steak, or pork chops. It’s also rich enough to stand as a vegetarian main course when served alongside a simple green salad with a vinaigrette dressing.
Storing and Reheating Leftovers
Store any leftovers in an airtight container in the refrigerator for up to 4 days. To reheat, place the desired portion in an oven-safe dish and bake at 350°F (175°C) for 15-20 minutes, or until heated through. You can add a splash of cream or broth to prevent it from drying out.
Frequently Asked Questions
Yes! You can assemble the entire casserole a day in advance. Cover it tightly with foil and refrigerate. You may need to add 10-15 minutes to the baking time when cooking from cold.
The key is low heat and patience. Cook the onions slowly in butter and oil for at least 30-40 minutes, stirring occasionally. Don’t rush them, as this develops their deep, sweet flavor.
Starchy or all-purpose potatoes like Russets or Yukon Golds are best. They break down just enough to create a creamy texture while still holding their shape.
If you can’t find Gruyère, a good substitute would be a combination of sharp white cheddar and Parmesan. Jarlsberg or a classic Swiss cheese would also work well.
It’s a fantastic side dish for roasted chicken, steak, or pork loin. It can also be a vegetarian main course served with a simple green salad.
Share Your Creation!
We are absolutely certain you will adore this French Onion Potato Bake recipe. If you make it, please leave a comment below and let us know how it turned out! We love seeing your creations. Don’t forget to save this recipe to your favorite board on Pinterest!
French Onion Potato Bake Recipe
French Onion Potato Bake: The Ultimate Cheesy & Savory Casserole
Ingredients
Equipment
Method
- In a large skillet over medium-low heat, melt butter and olive oil. Add onions and a pinch of salt. Cook, stirring occasionally, for 30-40 minutes until deep golden brown and jammy. Add garlic and thyme and cook for 1 more minute. Deglaze with white wine, if using, and simmer until evaporated.
- Preheat oven to 400°F (200°C). Butter a 9x13 inch baking dish. Slice potatoes thinly and uniformly.
- In a large bowl, whisk together heavy cream, beef broth, salt, and pepper.
- Layer one-third of the potatoes in the baking dish. Top with half the onions and one-third of the cheese. Repeat the layers. Finish with the last layer of potatoes.
- Pour the cream mixture evenly over the potatoes. Top with the remaining cheese. Bake for 50-60 minutes until potatoes are tender and the top is golden and bubbly.
- Let the bake rest for 10 minutes before serving to allow the sauce to set.
Notes
Don't rush the onion caramelization; it is the key to the dish's deep flavor.
Feel free to substitute Gruyère with a sharp white cheddar or a mix of Swiss and Parmesan cheese.
