Potatoes au gratin makes the perfect potato side dish for Sunday supper or as a make-ahead holiday side dish! Layers of potatoes and onions are baked in a rich, cheesy sauce until bubbly and golden brown.
This post may contain affiliate links. Please read our disclosure policy.
Holly’s Recipe Highlights
This Potatoes au Gratin recipe makes easy cheesy potatoes, similar to scalloped potatoes but loaded with rich cheesy flavor. They are the perfect holiday dish next to a baked ham or even a Roast Beef Tenderloin or pork tenderloin!
- Flavor: Creamy, cheesy, and comforting with a golden, slightly crispy top that makes every bite irresistible.
- Recommended Tools: To save time on prep and make even and thin potato and onion slices, use a mandoline or the side of a box grater.
- Budget Tip: You can swap Gruyère for provolone or Swiss and still get that melty, flavorful goodness.
- Time-Saving Tip: If you’re short on time, check the recipe notes below to reduce cooking time.
Scalloped Potatoes vs Potatoes au Gratin
So what is the difference between scalloped potatoes and au gratin potatoes? They’re both very similar, containing potatoes (and often onions) baked in a creamy sauce. Au Gratin is defined as covered with breadcrumbs or cheese, scalloped refers to “bake with milk or a sauce”.
In the case of this recipe, the difference is the cheese. That being said, the term scalloped potatoes is still often used if there is cheese within the dish!
The Best Kind of Potato to Use for Potatoes au Gratin
Just like when making scalloped potatoes, the best potatoes for gratin are red-skinned or Yukon gold potatoes. These two waxy potatoes can hold their shape well, and because they’re thin-skinned, they do not require peeling (extra bonus!).
While russet potatoes or baking potatoes taste good, they’re more starchy. They do not hold their shape as well, and the dish can become mushy; they’re more suited to mashed potatoes.
Cheese for Potatoes au Gratin
What is the best cheese for potatoes au gratin? When making Gratin potatoes, choose cheeses that have lots of bold flavors. Our top choices are varieties with a sharper flavor, including sharp cheddar and Gruyere.
Gruyere cheese adds a rich flavor to au gratin potatoes that truly cannot be matched; if you can get it, I highly recommend that you do! If Gruyere isn’t available, use provolone or Swiss for a similar flavor!
How to Make Potatoes Au Gratin
Potatoes Au Gratin has tender potatoes in a creamy, cheesy sauce for a dish that everyone loves.
- Prep: Thinly slice the potatoes and onions.
- Assemble: Stack the potato slices and onions in little piles and then stand them on their sides in the casserole dish.
- Sauce: Cook the cheese sauce in a saucepan over medium heat until smooth and creamy (full recipe below), then pour it over the potato and onion slices.
- Bake: Bake until the potatoes are tender and the sauce is bubbly.
Second Day Servings
- Leftover potatoes au gratin will keep in the refrigerator for up to 4 days. Let it cool completely, then cover tightly with plastic wrap, or transfer to an airtight container before refrigerating.
- To freeze, allow it to cool completely and wrap the dish well with both plastic wrap and aluminum foil, or portion it into freezer-safe containers. It will keep for up to 2 months in the freezer.
- For best results, thaw overnight in the refrigerator before reheating. Reheat covered in the oven at 350°F until hot throughout (about 20 to 30 minutes), removing the cover near the end to crisp up the top again.
- Avoid microwaving frozen potatoes, as it can make the sauce grainy and the potatoes watery.
More Holiday Side Dishes
Did you make this Potatoes au Gratin recipe? Leave us a rating and a comment below.
Ingredients
- 2½ pounds red potatoes
- 1 medium 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 thinly 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.
- In a saucepan, melt butter and flour and cook for 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 the stacks to allow the sauce to seep between the layers. Cover with foil (sprayed with cooking spray) and bake for 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
- Slice potatoes as thinly as possible.
- Shred your own cheese from a block for the best results. Fresh herbs (such as thyme or rosemary) and garlic can be added to the sauce if desired.
- To reduce baking time, wrap a microwave-safe casserole dish in plastic wrap before adding the cheese sauce and microwave on full power for about 10 minutes (be careful, it will be hot when removing the plastic wrap). Add the cheese sauce and bake as directed for about 45-55 minutes.
- Additional cheese (cheddar or parmesan) can be sprinkled on top once the foil is removed if desired.
- Store leftovers in an airtight container for up to 4 days. Reheat in the oven or the microwave.
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.
This turned out so good!! Simple yet delicious!! Just make sure you leave enough time for prep & cooking.
This is a huge hit every time I make it!
I used all gruyere cheese rather than the mix and added about 1/2 tsp of dried thyme to the recipe. ABSOLUTELY DELICIOUS!
DELISH!
I also enjoy the versatility of this recipe.
I was able to use it as a base for a soup I made. So satisfying!
Made this recipe tonight and added the suggested ingredients of rosemary and thyme. I must say the dish was amazing! I taught culinary arts for 8 years and this is hands down the best recipe for this dish I have tasted.
Amazing recipe. I would add some garlic powder to give it some more flavor next time.
So so good. I excluded the onions and added a little bit of fresh tarragon and chives at the end. Used Gruyère as the cheese. Absolutely divine!
Thank you so much, Wendy! ❤️
Followed recipe except used russet potatoes. Very good, empty dish so was a success. TY.
Delicious recipe! I made these for Christmas and they turned out fabulous. Thank you.
I cut the recipe in half for just 4 of us and it was perfect and delicious. I will definitely save this and make it again.
can you make these in a slow cooker?
I haven’t tried this recipe in a slow cooker so I can’t say for sure – dairy doesn’t always hold up in the slow cooker. I use this recipe for making slow cooker potatoes.
Is it possible to par bake, or partially bake, the dish the day before, then finish it just before the meal? If so, what combo of cooking times would you recommend? Thank you! Love the edge-up presentation you created.
I haven’t tried par baking but I do think it would work well with this dish. My estimate would be to bake them for the 60 minutes and then about 30 to 40 minutes the next day. As I haven’t tried it you might allow for extra time just in case, they will stay hot for quite a while. Let us know how it goes!
Tommy, did you try par baking? If so did it turn out okay? I’m hoping you say yes because this would make my day tomorrow much less busy. Thanks!
Excellent recipe, very delicious, but needs at least 25% more sauce.
Adding: I forgot that the potatoes weren’t quite tender at the end of the cooking time, so they got an extra 15 minutes in the oven. And I did make this the day before serving, it worked out very well.
Could this be done in a roaster oven or crockpot?
I have never tried but you should be able to make them in a crockpot. I would follow the cooking instructions on this crockpot scalloped potatoes recipe and cook these the same way. Enjoy!
Thank you for your response. Could i also cook for longer at a lower temperature? We have our meat cooking at 325.
This would be fine cooked longer at a lower temperature but I can’t say for sure how long. I would allow for extra time as they’ll stay hot for quite a while if they’re done early.
I am planning to make these for Christmas! They sound so good!! Can these be put together the night before and baked the next day?
Hi Julie, yes it can be made ahead! Prepare as directed and cool. Once cool, cover with plastic wrap and refrigerate. I would suggest removing from the fridge at least 30 minutes before baking. It may need a little bit extra cook time. Enjoy!
Hi! Im excited to try this recipe!! I was wondering, can I use almond milk for this recipe?
Thank you!
Hi Claire, yes you can use almond milk in this recipe. We would love to hear how it turns out for you!
Can I make this gluten free? If so, would you sub 1:1 flour or use almond flour?
Hi Emily, I have never tried making this dish GF but other readers have used gluten free flour or cornstarch instead with good results. Let us know how it turns out for you!
I plan to make these for Easter. Regarding your gluten free comment that cornstarch or almond flour can be used instead of flour, would one be better than the other? And what amount if cornstarch? Thank you!
To Tanja, A gluten free 1:1 flour would be your best option. And you can replace it with the same quantities as listed for flour in the recipe.
Question… I don’t need to peel the potatoes first? Can I use russets? I can’t wait to try this in a few days!
No need to peel thin skinned potatoes, I would peel russets. You can use russets but they tend to fall apart. You can also find this information in the post:
Just like when making scalloped potatoes, the best potatoes for gratin are red-skinned or Yukon gold potatoes. These two waxy potatoes can hold their shape well and because they’re thin-skinned, they do not require peeling (extra bonus!). While russet potatoes or baking potatoes taste good, they’re more starchy. They do not hold their shape as well and the dish can become mushy, they’re more suited to mashed potatoes.
I have avoided au gratin recipes due to the amount of work they require. This recipe is well worth it! I added some garlic powder and thyme along with salt and pepper and they were fantastic. I will definitely make them again!
Cannot wait to try this recipe for Christmas but a concern of mine is that it will not be seasoned enough for everybody.
Have you ever added cream of mushroom or celery soup to the sauce mix ( condensed, right out of the can) ?
I will definitely add garlic but we do not like Thyme.
Hi Roy, I have never tried adding condensed soup so I can’t say for sure. Please let us know how it turns out if you decide to try it!