Potatoes au Gratin are the ULTIMATE cozy potato casserole
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.
- 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)
- 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.
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! All recipes are rigorously tested in our Nashville Test Kitchen to ensure they are easy, affordable, and delicious.
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.
Nutrition Information
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.