When you need pure comfort in a casserole dish, Potatoes Au Gratin delivers. These thinly sliced potatoes baked in a creamy, cheesy sauce hit all the comfort food buttons. And the leftovers are awesome, so you can feed on that casserole heaven all week. So don’t sleep on this classic potato casserole and definitely don’t save it just for holidays like Thanksgiving. You need to be making this Potatoes Au Gratin recipe year ’round!
What are Potatoes Au Gratin?
Potatoes au gratin are thinly sliced potatoes layered with cheese and a creamy white sauce, then baked until bubbly and delicious. It’s pretty incredible. Or, if you’re familiar with scalloped potatoes, potatoes au gratin is basically just scalloped potatoes with cheese (haha, that made me think of “royale with cheese”). They’re rich, creamy, cheesy potato casserole heaven.
Ingredients for Potatoes Au Gratin
Here’s what you’ll need to make this incredible Potatoes au Grain recipe:
- Potatoes: We used russet potatoes for this casserole because the high starch content keeps the sauce nice and thick, and I prefer how soft they get compared to a waxier potato variety, like Yukon gold.
- Onion: Yellow onions sautéed in butter gives the creamy sauce a deliciously savory flavor base.
- Butter: You can’t have a rich and creamy sauce without some butter!
- All-purpose flour: Flour combines with the butter to create a roux, which thickens the creamy sauce.
- Chicken broth: Broth provides flavor depth to the casserole and contributes salt, which helps properly season the sauce and potatoes.
- Milk: Whole milk is the base for the creamy sauce. I do not recommend using low fat milk or else the sauce will not be as creamy.
- Cheese: To make the casserole extra rich and delicious, we layer in cheese with the creamy sauce to take it over the top. We used cheddar, but you can experiment with different cheeses.
- Seasoning: This potato casserole is seasoned simply with salt, pepper, and a little nutmeg.
What Kind of Cheese Can I Use?
In general, you want to stick to smooth melting cheeses for potatoes au gratin and avoid hard aged cheeses that don’t melt as easily (like Parmesan, although that would make a nice topper mixed with breadcrumbs!). I had some cheddar cheese on hand today, that I used, but Gruyere is another popular choice for potatoes au gratin.
What to Serve with Potatoes Au Gratin
This is such a rich comforting dish that it pairs well with any roasted or baked comfort food. I would pair it with something like Herb Roasted Pork Tenderloin, Cheddar Cheeseburger Meatloaf, or Herb Butter Chicken Thighs. And of course you’ll probably need some sort of vegetable to balance out all that richness, so add a simple side of steamed green beans for good measure. Potatoes au Gratin are also a fantastic side dish to add to holiday meals like Thanksgiving, Christmas, and Easter.
Potatoes Au Gratin
Servings 8Ingredients
- 3 lbs. potatoes ($1.79)
- 1 yellow onion ($0.32)
- 4 Tbsp butter ($0.56)
- 4 Tbsp all-purpose flour ($0.04)
- 1 cup chicken broth ($0.12)
- 2 cups whole milk ($0.75)
- 1/2 tsp salt ($0.02)
- 1/4 tsp freshly cracked black pepper ($0.02)
- 1/8 tsp ground nutmeg ($0.02)
- 8 oz. cheddar, shredded ($1.69)
Instructions
- Preheat the oven to 350ºF. Peel and slice the potatoes into ⅛-inch thick slices. If you're not yet confident in your knife skills, use a mandoline or food processor to slice the potatoes into thin, even pieces.
- Finely dice the yellow onion. Sauté the onion in a sauce pot with the butter until soft (about five minutes). Once soft, add the flour to the pot and continue to cook and stir for about two minutes. Finally, whisk in the milk until the flour is fully dissolved.
- Allow the milk to come up to a gentle simmer over medium heat, whisking often. Once simmering, the milk with thicken. Whisk in the chicken broth and allow it to come back to a simmer. Season the sauce with salt, pepper, and nutmeg.
- Layer half of the potatoes in the bottom of a 4 quart casserole dish. Top the potatoes with half of the white sauce and half of the shredded cheddar. Repeat with one more layer of potatoes, sauce, and shredded cheddar.
- Cover the casserole dish with foil and bake in the preheated 350ºF oven for 45 minutes. Remove the foil and continue to bake for another 30 minutes, or until the cheese is browned and bubbling on top. Let the casserole stand at room temperature for 10 minutes before serving.
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Nutrition
How to Make Potatoes Au Gratin – Step by Step Photos
Preheat the oven to 350ºF. Peel and slice three pounds of potatoes into ⅛-inch thick rounds. If you’re not confident in your knife skills, you can use a mandoline or food processor with a slicer attachment to create the thin, even slices.
Finely dice one yellow onion. Sauté the onion with 4 Tbsp butter in a sauce pot until the onions are tender (about 5 minutes).
Add 4 Tbsp flour to the pot with the sautéed onions and continue to cook and stir over medium heat for about two more minutes.
Whisk 2 cups milk into the pot with the onions and flour. Whisk well until all the flour is dissolved. Allow the milk to come up to a gentle simmer, at which point it will thicken.
Whisk in 1 cup chicken broth and allow it to come back up to a simmer.
Season the white sauce with ¼ tsp salt, ¼ tsp freshly cracked black pepper, and ⅛ tsp ground nutmeg.
Layer half of the sliced potatoes in a 4-quart casserole dish. top with half of the white sauce and 4oz. shredded cheddar.
Repeat all three layers one more time: sliced potatoes, white sauce, and shredded cheese. Cover the casserole dish with foil and bake for 45 minutes in the preheated 350ºF oven.
Remove the foil after 45 minutes and bake without foil for an additional 30 minutes. Let the potatoes stand at room temperature for about 10 minutes before serving. Enjoy!
I garnished the Potatoes au Gratin with a little parsley for color, but parsley is not needed to flavor this dish.
I used unsweetened almond milk and it worked great, sauce was still creamy.
Tested this last night in a head-to-head with Kenji Lopez-Alt’s Hasselback Potato Gratin, and for us Beth’s recipe was the definite winner for Thanksgiving. We enjoyed delightfully cooked potatoes, gooey cheese, and a sauce that held up much better than Kenji’s recipe. Changes I made: used half-and-half instead of milk, light layers of the sauce in between each layer of potato (using a thicker layer and cheese at the halfway point and end, as instructed). Since I have a convection oven I only baked this for 30 minutes foil-on and 30 minutes foil-off, which was perfect. This dish reminds me of the boxed au gratin my mom used to make, only MUCH better!
Halved the recipe because I don’t have a casserole dish of the right size, so I baked it in a 10″ cast iron pan, which was the perfect size. Also used gruyere for the cheese, because it was what I had. Baked 38 minutes with foil, then 22 without, and the doneness is just about perfect. Could’ve used a hint more salt, but that’s probably because I used a less-salty cheese. Definitely the best homemade au gratin I’ve made, and I hope this helps anyone else making a smaller batch!
Made this in the weekend with cauliflower florets instead of potatoes, it was absolutely amazing! Even my boyfriend loved it. Gratin anything seemed too intimidating for me until now, but this is a very flavourfull and easy recipe to follow. Thank you!
This sounds delicious! Did you change anything else when you made it with cauliflower, or did you just swap that and keep everything else the same?
Potato is one of my favorite vegetables, boiling it or frying it is making me happy every day in my life, I am so thankful that I found this recipe I didn’t know that you can elevate the awesome taste of potato by making a Gratin. Also, the step by step images makes it look easy to cook this recipe. Thank you for sharing this, perfectly splendid!
Made this in a 9×13 pan, which seemed to do the trick. It was good, but I don’t think the broth helped the dish. Also, the recipe took me longer than the stated 1 hr 40 minutes (2 ish hours). It took me more than 15 to prep all the potatoes, grate the cheese, chop the onion, and make the white sauce.
Wonderful Recipe To Prepare in the Party Times. Photos and Your Blogs are Looking Nice. I’ll Definitely Try it. Thank You For Sharing.
sooo good, but I think maybe I used the wrong setting with my mandolin and made the slices too thick. I had to bake it for an hour longer than the recipe says to get the potatoes cooked through. Will definitely make this again soon with a thinner slice to test it out, it goes wonderfully with a nice steak!
Could I make this the day before? Or even just do everything the night before then bake the day of?
I haven’t tried that, so I’m not sure. Sometimes you can have issues with the salt in the sauce pulling water out of the potatoes and making it watery, but I’m not sure if that would happen here without testing it. One other thing to consider is that if it’s chilled when going into the oven, you may need to bake longer.
I, too, like using russets for this dish as they absorb the sauce well, and I always add plenty of onion which seems to have a natural affinity for potato dishes. For a richer, company version, use cream or half and half for part of the milk. Gruyere or Swiss are also good, although I usually use cheddar, not only because it tastes great, but also because of the cheery bright color. I’ve even used smoked gouda, which was delicious, too. A perfect recipe with tons of flexibility.
Looks Good. Also fyi, the recipe images are not showing up on the search results page anymore
Thanks for the heads up! I’ll have my tech guy look into that. :)
I still have this problem :(
Okay, try it again and see if the issue is still happening. :) We switched tech companies this past week and a lot of settings got changed, so this problem came back in the process, but I noticed it yesterday and they fixed it again (after your comment, I believe) so see if you’re still having the problem now. :)
What a fabulous recipe! So easy and tasty! I’ll definitely be making this one again!
Thank you so much for the recipe!
Hi! Looks yummy but I’m not a fan of nutmeg. What does it do to/for the flavor?
It just sort of enhances the creaminess and adds a slight depth of flavor. Since it’s such a small amount you don’t detect the actual nutmeg flavor, it just adds a subtle enhancement to the other flavors.
Yum, yum Beth! Have you ever used any nut milks in place of dairy for this recipe? I wonder if they would have enough fat for the sauce? We rarely use dairy anymore (though I would use “real” cheese!)
I haven’t tried any dairy alternative milks for white sauces like this, unfortunately!
I have used plain nondairy coffee creamer in other recipes calling for milk. It does contain whey, but no lactose to set off my stomach. It works in instant au gratin boxed potatoes. I need to see if it works in this recipe from scratch. Nut milks may add an unwanted flavor, but please give it a try & report back!
How big of a casserole dish do you recommend?
4 quart :)
Please send me the best recipe. My friend is a hospital kitchen worker and would love to surprise her patience with something so yummy