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.
In the oven as we speak, doubled the recipe ♀️
Such a delightful and detailed recipe! I love the helpful tips like using a mandoline for even slices and the make-ahead instructions. Can’t wait to try this creamy, cheesy goodness for a cozy family dinner
So this is the fourth or fifth time I’ve made this recipe. Each time I’ve changed it slightly. Easter, I think I had it perfect. I substituted Scallions for onions (sweeter) and used 1 1/2 cups Gruyere and 1/2 cup finely grated Parmesan; finally, I substituted one of the cups of milk with buttermilk and added a tablespoon of Garlic and a teaspoon of Italian herbs. It’s absolutely amazing. It has a bit more flavor than the basic recipe, but is not overpowering at all.
this recipe is amazing! Thank you for sharing!
When preparing these a day in advance advance, do you bake the dish after you pour the cheese sauce on since the potatoes are now warmed from the cheese sauce and simply reheat the next day, or cover the raw potatoes with the hot cheese sauce, immediately refrigerate and then bake the next day? Thank you!
When making in advance, as long as the potatoes are completely covered in the sauce you do not need to bake it first. I generally pour the sauce overtop and cool slightly (while I clean up) before refrigerating. Remove from the fridge at least 30 minutes before baking adding 10 to 20 minutes to the baking time in the recipe.
Made this once and making again tonight my boyfriend requested is as I’ll be out of town and he wanted this dish to snack on. First time around was a success so will this! Thank you!
Thanks for this recipe. I cooked baked potatoes using your recipe for the oven. I then used this recipe and added a can of cream of mushroom soup for the sauce and threw in some crawfish. We served it on top of the baked potatoes. It was absolutely delicious. It was served on the side of your braised thighs with mushrooms.
I 4x the recipe for a 10lb bag of potatoes and it turned out perfect.
brilliant
Thank you, Kevin. I am glad you enjoyed it.
I thought at first it was a little time consuming but now I don’t mind it at all, worth the time!! It’s so delicious. I’ll be making it many more times I’m sure ❤️❤️❤️
this is wonderful, I added some carrots, cauliflower and broccoli.. great dinner!!
I made these exactly as written, and they were amazing! Everyone commented on how good they were, and there was none left.
I made this for a 50s dinner party. I had never made this dish before. I was a big success. I forgot the mustard. And next time I will make more cheese sauce.
excellent
very nice l add a little cheese
Amazing recipe!!!
These tasted bland. I used Yukon gold potatoes and omitted the onions. I added rosemary to the cheese sauce for some extra flavor. I did shred my own cheeses as well. Not sure what happened.
omitting the onions is the mistake. onions give the best flavor to most dishes. If your not an onion fan just chop them up in a electric chopper until basically mush almost liquefied then add it. you won’t notice the onion but the flavor will be there.
These potatoes are fantastic. My family wanted a potato dish for Easter and I chose this one after searching online. I am not crazy about potatoes but I had two helpings.
I used a combination of Cheddar , Swiss and Parmesan . I used pre shredded- my brand doesn’t have any additives so no problems with melting .
Can I use heavy cream instead of milk?
I haven’t tried it so can’t say for certain but it will likely be a bit thicker with heavy cream. You could substitute half with low sodium broth as well. If you do use heavy cream and it’s too thick, you can thin it out with a bit of water or broth. Let us know how it goes!
Made this today. It was great.i included some chopped bell pepper.