French Onion Potatoes are one of those side dishes that seem to show up everywhere once you start paying attention.

Potlucks, family dinners, holiday spreads—
you name it. And honestly, it’s not hard to see why.

The combination is simple but incredibly satisfying: tender potatoes baked in a rich oniony sauce,
finished with a layer of melted cheese.

It’s the kind of dish people keep going back for,scooping up just one more spoonful.

What makes this version especially appealing is how little effort it takes to pull together.
There’s no complicated prep or long list of ingredients—just a straightforward method

that delivers big, comforting flavor.

If you’re looking for an easy, crowd-pleasing side that practically cooks itself,
this is one to keep in your rotation.

For French Onion Potatoes

Russet Potatoes – these hold their shape well while baking and turn perfectly tender without falling apart.
Condensed French Onion Soup – the base of the dish, adding deep, savory onion flavor and richness.
Dry Onion Soup Mix – boosts the overall flavor and adds that classic oniony seasoning throughout the potatoes.
Butter – melts into the sauce and gives the potatoes a rich, smooth texture as they bake.
Gruyere Cheese – melts beautifully over the top and adds a slightly nutty, creamy finish (Swiss or provolone work too).

The Best French Onion Potatoes Casserole

A simple, comforting casserole made with just five ingredients. Soft, bite-sized potatoes bake in a rich onion-infused butter sauce and are finished with a layer of melted cheese for an easy, satisfying side dish.

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Course: casserole, Side Dish

Cuisine: American

Keyword: The Best French Onion Potatoes Casserole

Prep Time: 15

Cook Time: 1

Total Time: 1 15

Servings:

Notes

Ingredients

1 10-oz can French onion soup
1 1-oz envelope dry onion soup mix
1/2 cup (1 stick) butter, melted
2.5 lbs russet potatoes
2 cups shredded gruyere cheese

Instructions

Preheat oven to 375 degrees.
Combine condensed soup, dry soup mix and melted butter in a large bowl then stir well.
Peel potatoes then cut into 1-inch pieces. Add potatoes to the soup mixture then stir to coat.
Pour everything into a 13x9 baking dish then spread potatoes evenly into dish.
Cover tightly with aluminum foil then bake at 375 degrees for 30 minutes.
Remove foil then continue cooking for 30-45 minutes or until potatoes are tender, stirring 2-3 times to ensure the potatoes cook evenly.
Top with shredded cheese, cover dish tightly with foil then let potatoes rest for about 5-10 minutes to soak up the soup mixture and allow for the cheese to melt.

Notes

Do not prepare the condensed soup or soup mix – just add to the recipe as-is.
I used 6 medium-large potatoes in this batch. You’ll just want enough potatoes to cover the bottom of a 13x9 baking dish.
Substitute Swiss cheese or provolone for the gruyere if desired.
Feel free to add more cheese! Four ounces yields about 2 cups of shredded cheese.
You can only double the recipe if you have a baking dish large enough for the potatoes to remain in a single layer.
I don’t think these could be cooked in a crock pot but if you prove me wrong, comment below to let us know!

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Why are my potatoes not soft yet?
Potatoes can take a little longer depending on their size and your oven. They should be fork-tender when done. If they’re still firm, just keep baking a bit longer and check every 10 minutes until perfectly soft.
Can I make this ahead of time?
Yes! You can assemble everything in the baking dish, cover, and refrigerate. When you’re ready to bake, pop it in the oven and add a few extra minutes since it’s starting cold.
Do I have to peel the potatoes?
Peeling gives you a softer, more classic texture, but you can absolutely leave the skins on. Just scrub them well and you’re good to go.
Why do I bake it covered first?
Covering the dish helps the potatoes steam and cook through evenly. Once they’re tender, removing the foil allows the sauce to thicken and the flavors to concentrate.
Can I use a different type of potato?
You can, but russet potatoes work best because they get tender and soak up all that flavor. Other varieties may be slightly firmer, but still delicious.