Potatoes au gratin are an easy cheesy way to make potatoes. Layers of potatoes and onions are baked in a rich cheesy sauce until bubbly.
Holly’s Recipe Highlights For Potatoes Au Gratin
- Flavor: Potatoes au gratin are an easy cheesy version of scalloped potatoes. They’ve got a cheese sauce while scalloped potatoes have a white sauce.
- Skill level: This recipe has a few steps, including slicing the potatoes and making a homemade cheese sauce. It isn’t difficult, but it does take time.
- Recommended tools: To save a lot of time on prep and and make even thin slices, use a mandoline.
- Budget tip: Any variety of cheese can be used; ensure you’re using a bold flavored cheese.
- Time-Saving Tip: If you’re short on time, check the recipe notes to reduce cooking time.
Ingredient Tips for Potatoes au Gratin
- Choosing Potatoes: The best potatoes for potatoes au gratin are waxy potatoes like red-skinned or Yukon gold. They hold their shape well, and because they’re thin-skinned, they do not require peeling (extra bonus!).
- Note: While russet potatoes or baking potatoes will work and taste good in this recipe, they’re more starchy and may fall apart once cooked—they’re best saved for mashed potatoes.
- Onion: Thinly sliced onion adds flavor. For a milder onion flavor, cook it in butter before layering or replace sliced onion with 1 teaspoon of onion powder in the sauce.
- Cheese: Use cheese with a bold flavor in this recipe—I use cheddar and Gruyere and sometimes sprinkle a little Parmesan on top.
- Option: Gruyère cheese can be replaced with provolone or Swiss for a similar flavor.
- Sauce: Made with butter, flour, and milk, this roux-based sauce is finished with shredded cheese.
How to Make Potatoes Au Gratin
Here is a quick overview of the steps for potatoes au gratin.
- Prep: Thinly slice the potatoes and onions.
- Sauce: Make the cheese sauce in a saucepan on the stove.
- Assemble: Stack the potato slices and onions in little piles and then stand them on their sides in the casserole dish.
- Bake: Bake until the potatoes are tender and the sauce is bubbly.
Find the full detailed recipe below.
How to Make Potatoes au Gratin Ahead of Time
This dish can be made 24 hours in advance. Ensure the potatoes are completely covered in the sauce—any exposed bits of potatoes will discolor slightly. Cover tightly with plastic wrap and refrigerate.
Remove from the fridge at least 30 minutes before baking. You may need to add 10 to 20 minutes to the baking time.
While we often eat these as a side, I sometimes make Potatoes au Gratin with ham by including slices or diced leftover ham (from our favorite crock pot ham) before baking.
Did you make this Potatoes au Gratin recipe? Leave us a rating and a comment below.
Potatoes Au Gratin
Ingredients
- 2 ½ pounds red potatoes
- 1 onion thinly sliced
- 3 tablespoons butter
- 3 tablespoons all-purpose flour
- 1 teaspoon dry mustard powder
- 2 cups milk
- 1 cup shredded cheddar cheese
- ½ cup shredded gruyere cheese
- ¾ teaspoon salt divided
- ½ teaspoon black pepper divided
Instructions
- Preheat oven to 400°F.
- Wash potatoes and slice into ⅛" thin slices. Slice onion as thin as possible.
- Season the potatoes and onions with ½ teaspoon of salt and ¼ teaspoon of pepper. Toss well to evenly coat. Layer potatoes and onions into little stacks. Place stacks on their side in a greased 2.5qt to 3qt casserole dish.
- Melt butter and flour in a saucepan and cook 2 to 3 minutes. Add mustard powder, ¼ teaspoon salt, ¼ teaspoon pepper and milk. Whisk over medium heat until thick and bubbly. Remove from heat and stir in cheeses until melted.
- Pour the cheese sauce over the potatoes, gently separating them to allow the sauce to seep between the layers. Cover with foil (sprayed with cooking spray) and bake 60 minutes.
- Remove foil and bake an additional 20 to 30 minutes or until lightly browned and potatoes are cooked. Cool 15 minutes before serving.
Video
Notes
Nutrition Information
Nutrition information provided is an estimate and will vary based on cooking methods and brands of ingredients used.
Course Side Dish
Cuisine American, French© SpendWithPennies.com. Content and photographs are copyright protected. Sharing of this recipe is both encouraged and appreciated. Copying and/or pasting full recipes to any social media is strictly prohibited. Please view my photo use policy here.
I’m trying this recipe today for Easter Dinner. You mentioned you use Parmesan cheese, how much do you use? And do you add it in when melting the other cheese? Thanks!
I sprinkle it on top, about 3 tablespoons.
Can I make this recipe the day before baking it?
It looks delicious!!!!
Yes, the prep ahead directions are listed in the post. Enjoy and let us know how it goes!
This dish can be made 24 hours in advance. Ensure the potatoes are completely covered in the sauce—any exposed bits of potatoes will discolor slightly. Cover tightly with plastic wrap and refrigerate.
Remove from the fridge at least 30 minutes before baking. You may need to add 10 to 20 minutes to the baking time.
Has anyone tried to bake ahead for the 60 minutes, refrigerate, and then bake the last 20 uncovered at a later time? I want to make ahead to bring for Easter, and think I would have to bake uncovered longer if it starts cold.
Potatoes hold their heat for quite a while so if you’d like you can allow for extra time. If they’re ready early, they should keep warm for a while.
easy, delicious, quick enough for busy days
I live with and help take care of my grandparents. Very thankful for Holly and her recipes, as she helps me with many meals!
These potatoes were the best my grandparents and I have ever had! They wanted to make sure I told Holly thank you!
I want to try this recipe, it looks delicious! The only Gruyere I was able to find was very expensive. Do you think Cheddar and Gouda would work instead of Cheddar and Gruyere?
Hi Vivian, swiss cheese is a good replacement for gruyere. You can try gouda or a white sharp cheddar. It will change the flavor but it will still be delicious.
Outstanding receipe. Always receiving compliments when I make this! One question – What is considered a serving? Is it a cup, 1/2 cup? thank you
The nutritional information is for 1/8th of the recipe.
This was really good.A little time consuming, even with using a mandolin, but it was fun, making the stocks with the hubby. However, I did not care for my choice of cheeses. I used Gruyere and Swiss. The Gruyere was good, the Swiss not so much (super stringy) And I also used pre-shredded cheese, won’t be doing that again! My only problem was that the cheese sauce burned on the bottom. I didn’t think that would have happened since it was covered in foil for the first hour of cooking. I used a glass baking dish. Any thoughts on what might have happened?
The potatoes au gratin recipe is versatile so feel free to change up the cheeses to your liking (cheddar and gruyere is a great combo). I haven’t had the cheese burn in the bottom but generally bake on the middle rack in a ceramic dish similar to this one. I hope that helps!
Pre shredded cheese has a coating on it (maybe flour or cornstarch) so that it stays separated which changes the consistency when melted. We make fondue regularly and the recipe warns of using the pre shredded kind.
This recipe is absolute fire! It was such a hit with my family and probably the best potatoes I have ever had. 5 stars +++++