French Onion Potato Bake

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Prep: 10 minutes
Cook: 35 minutes
Total: 45 minutes

French Onion Potato Bake is rich, cozy, and layered with flavor. If you love the depth of a good French onion soup and the comfort of a cheesy potato casserole, this bake brings both together in one unforgettable side dish.

Potatoes are a staple in our dinner routine. Two favorites are my Cheesy Hash Brown Potatoes and my Loaded Potato Salad Recipe. Try them, you won’t be disappointed.

A serving of creamy Potato Bake with onions and herbs on a white plate, next to a baking dish and a striped kitchen towel.

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Why this French Onion Potato Bake Recipe is a Keeper

I love this recipe for easy cheesy potato bake because not only is it quick and easy, it’s also incredibly delicious. It’s a great recipe to add to a go-to dinner recipe stash.

  • Intense Savory Flavor: The dry onion soup mix infuses the heavy cream and potatoes with the deep, concentrated flavor of caramelized onions and beef broth, without the hours of simmering.
  • Ultimate Comfort Side: It’s a rich, creamy, and satisfying side dish that elevates any meal, particularly roasts, chicken, or steak.
  • Simple Assembly: Despite the impressive final result, the dish requires minimal prep, just slicing, mixing the sauce, and layering.
  • Great Textural Contrast: The potatoes cook up tender and creamy in the sauce, while the top gets a delicious golden crust from the Parmesan cheese. Feel free to add some sour cream for extra creamy sauce.

What Kind of Potatoes are Best for this Side Dish?

A delicious Potato Bake gratin with sliced potatoes and onions, garnished with parsley, served in a white casserole dish with a wooden spoon.

The best sliced potatoes to use in this comfort food recipe are Yukon gold or Russet potatoes.

Pro Tip for Baked Potato Casserole

Check for Tenderness: Before removing the foil for the final baking stage, pierce a potato slice with a fork or sharp knife. If it meets resistance, recover and bake for another 5-10 minutes before uncovering.

Ingredient Notes for this Cheesy Potato Bake

Potato recipes use easy, fresh ingredient list that pack a punch of flavor. They have everything you love, potatoes, cream and cheese.

Get the full printable recipe with specific measurements and directions in the recipe card below.

Five bowls on a marble surface contain all the ingredients you need for a classic Bake: sliced veggies, onions, grated cheese, cream, flour, and chopped parsley.
  • Potatoes: Use a waxy potato variety like Yukon golds.
  • Onion Soup Mix: When mixed with heavy cream, the onion soup will bring a ton of the delicious creamy flavor.
  • Shredded Cheese: The recipe calls for parmesan cheese, but you could toss in a handful of shredded cheddar cheese on top or another tasty cheese.

Variations and Substitutions for Potato Casserole

Easily customize the best side dish by experimenting. Take it to the next level by using different ingredients and trying different flavors.

  • Potatoes: Sweet potatoes (use 2 large), sliced rutabaga or turnip. Sweet potatoes will add a sweet/savory contrast. Root vegetables may need a slightly longer bake time.
  • Dry Onion Soup Mix: 1 cup caramelized fresh onions (cooked down), 1/2 cup of French Onion Dip + 1 teaspoon beef bouillon powder. The soup mix is key for convenience; the caramelized onions require 30-40 minutes of prep.
  • Grated Parmesan: Shredded Gruyere cheese, Shredded Swiss cheese, 1/4 cup blue cheese crumbles. Gruyere and Swiss are traditional for French onion soup. You an also add layers of sharp cheddar cheese for a cheesy potato casserole.
  • Layering: Add 1/2 cup cooked, crumbled bacon or diced ham between the layers. Added cheese and bacon result a “loaded” element and makes it more of a main dish.

How to Make Creamy Cheesy Potato Bake

This recipe comes together in 3 quick and easy steps. These baked cheesy potatoes are so good, this recipe quickly became one of my favorites.

Get the full printable recipe with specific measurements and directions in the recipe card below.

Three images: sliced potatoes on a cutting board with a knife, a mixing bowl with cream and seasonings for Potato Bake, and the same bowl with the mixture stirred and a spatula.
  1. Preheat Oven and Prep Pan: Preheat the oven and grease the casserole dish.
  2. Assemble Layers: Mix together the heavy cream and the onion soup mix. In the prepared casserole dish, layer half of the potatoes then half of the onions. Pour half of the soup mixture on, then repeat the layers of potato, onion and soup mix.
  3. Top and Bake: Top with parmesan cheese, cover with aluminum foil and bake for 20 minutes. Then, remove the foil and bake until the potatoes are tender. Sprinkle on the chopped parsley and allow to rest before serving.
Four steps of preparing a Potato Bake: sliced potatoes, sliced onions added, creamy sauce poured, and breadcrumbs sprinkled on top in a square white baking dish.

Make Ahead Suggestions to Make Potato Bake

I like to prepare ingredients ahead of time so that I don’t have to do all of the steps at once when I’m making dinner. 

  • The Sauce and Onions (Up to 24 hours): Slice the onion rings and mix the heavy cream and onion soup mix. Store both in separate airtight containers in the refrigerator.
  • Full Assembly (Day of): Peel and slice the potatoes, assemble the entire dish in the casserole dish, and cover it tightly with foil. Do not add the Parmesan cheese yet. Refrigerate until you’re ready to bake, or up to 4 hours.

Alternate Cooking Methods for Potatoes Au Gratin

Alternatively, you can make individual servings using your air fryer.

  • Individual Servings (Ramekins): Layer the potatoes, onions, and cream mixture into 4-6 individual ramekins. Bake at 400°F uncovered for 20-25 minutes, until tender and golden brown. Excellent for plating at a dinner party. Total bake time is shorter.
  • Air Fryer (Small Batch): Layer the ingredients in a small, air-fryer-safe baking dish. Cook at 350°F for 20-25 minutes, covering with foil for the first 10 minutes if needed to prevent burning. Ideal for 2 servings or a very small casserole dish.

Store, Reheat and Use Scalloped Potatoes

  • Store: Store cooled leftovers in the baking dish covered with foil, or transfer to an airtight container. Refrigerate for 3-4 days.The leftovers will firm up significantly as they cool.
  • Reheat: Place leftovers in an oven-safe dish, cover with foil, and bake at 350°F for 15-20 minutes until heated through.
    • Microwave: Microwaving to reheat is the quickest, but may result in slightly mushy potatoes. Adding a sprinkle of cheese and some thyme before oven reheating can help refresh these scalloped potatoes.
  • Use Leftovers: Mash the cold leftovers, form into patties, coat in Panko, and pan-fry until golden brown and hot. This turns them into crispy, thin potato slices.
    • Stuffed Omelets: Chop the leftover creamy potato bake and use it as a savory filling for an omelet or breakfast scramble.
    • Beef Side: Serve cold or slightly warm alongside thinly sliced leftover roast beef (like a potatoes au gratin or potato salad).

Recipe FAQS for Cheesy Potato Bake Recipe

How thin Should the Potatoes be Sliced?

The potatoes should be sliced pretty thin. I like to slice mine to about 1/8 inch slices.

Why Cover it for the First 20 Minutes?

It’s best to cover with foil over the top for some of the cooking time so that it doesn’t dry out.

A serving of creamy side garnished with chopped parsley on a white plate, set on a light wooden surface with a striped cloth in the background.

Tips for Making French Onion Casserole Recipe

It’s so easy to adapt this potato with thickened cream, garlic and onions.

  • Don’t Rinse the Potatoes: After slicing, do not rinse the potatoes. The natural starch on the slices is essential for thickening the heavy cream sauce and making the final dish rich and creamy.
  • Seasoning the Layers: Although the soup mix is salty, sprinkle a very light pinch of salt and pepper, garlic powder or onion powder over the potato and onion layers before adding the cream. This ensures every layer is seasoned, not just the sauce.
  • Set Time is Crucial: Do not skip the 5-minute resting period after baking. This allows the sauce to finish setting and prevents it from being runny when you serve it.
  • Ultimate French Onion Top: If you want a more authentic French Onion finish, substitute a 1/2 cup mix of shredded Swiss and Gruyère cheese for the Parmesan on top. Broil until bubbly and deeply golden brown
  • Serve These with the Best Potato Bake: Serve with Garlic Herb Eye of Round Roast, Creamy Risotto or Peanut Butter Stuffed Cookies.

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A serving of creamy Potato Bake with onions and herbs on a white plate, set beside a baking dish, wooden spoon, and a striped kitchen towel.

French Onion Potato Bake

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French Onion Potato Bake is an easy, layered casserole. The combination of onions, potatoes and a creamy sauce make for an irresistible weeknight meal.
Prep Time : 10 minutes
Cook Time : 35 minutes
Total Time : 45 minutes
Servings: 6 servings
Course: Side Dish

Equipment

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Ingredients
  

  • 2-3 large Potatoes, about 3 cups, peeled and sliced very thin
  • 1 Yellow onion, sliced into rings
  • 1 cup Heavy cream
  • 1 ounce Dry Onion Soup and Dip Mix, 1 packet
  • cup Parmesan cheese, grated
  • 1 Tablespoon Fresh parsley, chopped

Instructions
 

  • Preheat the oven to 400℉. Grease the casserole dish.
  • Peel and cut your potatoes, onion and parsley.
  • Stir the heavy cream and onion soup mix together in a medium bowl.
  • Layer half the potatoes, then half the onions.
  • Pour half the cream mixture over the potatoes and onions, then repeat and top with parmesan cheese.
  • Cover with aluminum foil and bake for 20 minutes.
  • Remove the aluminum foil, bake for an additional 15 minutes, until potatoes are tender.
  • Sprinkle with parsley, and allow to set for 5 minutes then serve.

Christina’s Notes

  • Yukon Gold or Russet Potatoes: Their creamy texture holds up well during baking and absorbs flavor beautifully.
  • Slice Thin and Even: Aim for ⅛-inch slices to ensure they cook evenly and layer smoothly.
  • Caramelize Low and Slow: This builds deep, sweet flavor that mimics classic French onion soup. Don’t rush this step—it’s the heart of the dish.
  • Layer with Care: Alternate potatoes, onions, and cheese to distribute flavor throughout. A little thyme or garlic between layers adds depth.
  • Choose Melty Cheese: Gruyere is traditional and adds nutty richness, but Swiss or mozzarella work well too.
  • Cover, then Uncover: Bake covered for most of the time to steam and soften the potatoes, then uncover to brown the top.
  • Let it Rest: Give it 10–15 minutes out of the oven to set up. This helps the layers hold together and makes slicing easier.
Helpful Tips for All RecipesThese quick tips will help you get perfect results every time.

  • Scale the recipe: Simply adjust the serving size in the recipe card and the ingredients will update automatically.
  • Make your own All Purpose Seasoning: When a recipe calls for All Purpose Seasoning, you can use my homemade All Purpose Seasoning recipe or substitute salt and pepper to taste.
  • Meat doneness: I always use a meat thermometer to test for doneness when cooking meat.
  • Use unsalted butter: I use unsalted butter so I can control the salt level in the recipe.
  • Preheat the oven: Unless otherwise noted, always preheat your oven before baking.

For more helpful information about this recipe, such as variations, substitutions and other pro-tips, check out the blog post.

Nutrition

Calories: 234kcalCarbohydrates: 19gProtein: 5gFat: 16gSaturated Fat: 10gPolyunsaturated Fat: 1gMonounsaturated Fat: 4gCholesterol: 50mgSodium: 493mgPotassium: 411mgFiber: 2gSugar: 3gVitamin A: 690IUVitamin C: 17mgCalcium: 96mgIron: 1mg
The nutritional information provided are estimates. It is recommended that you verify this information with your own trusted resource.
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