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Rich, comforting, and surprisingly simple, these potatoes au gratin are an irresistible side dish that always gets rave reviews.
This classic potatoes au gratin recipe is one of my favorite Thanksgiving side dishes, and it’s also fitting for Christmas, a dinner party, or any meal that calls for something a little extra. It involves layering thinly sliced potatoes with heavy cream and grated cheese in a casserole dish, and then baking until the cream thickens and blankets the potatoes in a rich, creamy sauce. And while it’s certainly worthy of a special occasion, honestly, a pan of these potatoes makes any dinner feel like one.
“I only gave this five stars because I couldn’t give it 10 stars. This may be my favorite side dish ever. It is amazing!”
Potatoes Au Gratin vs Scalloped Potatoes
Potatoes au gratin and scalloped potatoes are similar dishes, but there are a few key differences. Both are made with thinly sliced potatoes baked until tender, but au gratin potatoes typically include cheese and are known for their rich, golden-brown top. Scalloped potatoes traditionally don’t contain cheese and are often flavored with onions and baked in a milk or cream sauce thickened with a roux.
What You’ll Need To Make Potatoes Au Gratin
- Russet Potatoes: With their high starch content, russets soak up the cream beautifully and bake into soft, melt-in-your-mouth layers. They’re the best choice for this dish. Skip the Yukon Golds here—they won’t give you the same texture.
- Heavy Cream: The secret to the luscious, velvety sauce. You might be tempted to swap in milk or half-and-half, but don’t—this recipe really needs heavy cream to thicken properly.
- Parmigiano Reggiano: Adds a salty, nutty depth that melts right into the potatoes, creating incredible flavor and texture. Be sure to use true Parmigiano Reggiano. If you can’t find it, Pecorino Romano makes a great substitute.
- Salt, Pepper & Thyme: These simple seasonings bring everything to life—the thyme is optional but adds a subtle earthiness that pairs perfectly with the creamy potatoes and cheese.
- Jump to the printable recipe for precise measurements
How To Make Potatoes Au Gratin
Slice the potatoes: Slice the potatoes as thinly and uniformly as possible so they cook at the same rate. A mandoline works well, but a sharp knife is all you need. If a potato feels wobbly, cut a thin slice lengthwise and place it cut-side down on the cutting board to create a stable base.
Season the potatoes: Toss the slices thoroughly with salt and pepper so the seasoning is evenly distributed. Potatoes need a generous amount of salt to bring out their flavor, so don’t be tempted to skimp.
Assemble the gratin: Arrange the potatoes in overlapping layers in a buttered baking dish, distributing the cheese and cream evenly as you go. Don’t worry about making the layers perfectly neat, but try to keep them fairly even so the potatoes cook uniformly. Be sure to pour in all of the cream—it will thicken as the gratin bakes, creating the rich, velvety sauce.
Bake until golden: Bake the gratin until the top is deeply golden and a knife slides easily through the potatoes with almost no resistance. Don’t cover the dish with foil; baking it uncovered is what gives you that beautiful browned top. Let it rest for a few minutes before serving so the cream can settle and thicken around the potatoes.
Finish with a sprinkle of fresh thyme and serve hot, while the top is crisp and golden and the potatoes underneath are creamy and tender.
Potatoes au gratin are best baked just before serving, but you can do some of the work ahead. See the recipe card below for my make-ahead, storage, and reheating instructions. If you love this recipe, try my cauliflower gratin or Brussels sprouts gratin next.
More Potato Side Dishes You May Like
Potatoes Au Gratin
Ingredients
- Butter to grease the baking dish
- 2½ lb Russet potatoes (3 to 4), peeled and very thinly sliced
- 1½ teaspoons salt
- ¼ teaspoon freshly ground black pepper
- 1 cup (4 oz) finely grated Parmigiano-Reggiano
- 2¼ cups heavy cream
- Fresh thyme, for serving (optional)
Instructions
- Preheat the oven to 350°F (175°C) and set an oven rack in the middle position. Grease an 8-in (20-cm) or 2-qt/2L baking dish with butter.
- In a large mixing bowl, toss the potatoes with the salt and pepper until evenly coated.
- Arrange some of the potato slices, edges overlapping, in a single layer on the bottom of the prepared baking dish. Sprinkle a quarter of the cheese over the potatoes, and then pour a quarter of the cream over the cheese. Repeat with the remaining potatoes, cheese, and cream, forming 4 layers. Pour any leftover cream over top.
- Place in the oven and bake, uncovered, for 60 to 75 minutes, or until the potatoes are tender when pierced with a knife and golden brown on top. Let the dish settle on the counter for about ten minutes. Sprinkle with fresh thyme, if using, and then serve.
Notes
Nutrition Information
This website is written and produced for informational purposes only. I am not a certified nutritionist and the nutritional data on this site has not been evaluated or approved by a nutritionist or the Food and Drug Administration. Nutritional information is offered as a courtesy and should not be construed as a guarantee. The data is calculated through an online nutritional calculator, Edamam.com. Although I do my best to provide accurate nutritional information, these figures should be considered estimates only. Varying factors such as product types or brands purchased, natural fluctuations in fresh produce, and the way ingredients are processed change the effective nutritional information in any given recipe. Furthermore, different online calculators provide different results depending on their own nutrition fact sources and algorithms. To obtain the most accurate nutritional information in a given recipe, you should calculate the nutritional information with the actual ingredients used in your recipe, using your preferred nutrition calculator.
Gluten-Free Adaptable Note
To the best of my knowledge, all of the ingredients used in this recipe are gluten-free or widely available in gluten-free versions. There is hidden gluten in many foods; if you’re following a gluten-free diet or cooking for someone with gluten allergies, always read the labels of your ingredients to verify that they are gluten-free.
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disappointed. cream curdled between layers and looked like pieces of egg whites.
husband, the retired chef said that potatoes should have been parboiled before slicing, layering, etc. says starch from raw potatoes caused cream to curdle.
very good taste and will make again, but will boil potatoes a bit first. also sliced white onion on mandoline and sprinkled rings of onion between layers–delicious flavor added.
I have made this recipe many times and not had this issue. While your husband’s recipe is probably the foolproof method, it really is not necessary for the home cook. You should definitely try it again, being careful to follow the recipe this time and I’m sure you will get great results! Good luck!
Can it be cooked a day ahead and reheated so the potatoes don’t turn color?
Sure, Pam. Just reheat them, covered with foil, in a 350 oven for 20 min or until heated through. Hope you enjoy!
I would lik to make this recipe larger in a 9 by 12 dish, should I double the recipe? In particular the heavy cream.
Hi Joyce, yes, using that size pan would require doubling it, but if you plan to double it, I think you’ll have better results baking it in two smaller pans; they’ll cook more evenly that way. If you feel strongly about baking it in the 9 x 12, I’d add about 10 minutes to the baking time. Hope you enjoy!
Can this be made with lactaid milk instead of cream?
Unfortunately, milk won’t work very well in this recipe -sorry!
These are so simple to make but they turn out amazing!
Jenn, I’ve made these several times and family fight over the leftovers. They are just simply delicious and worth every calorie. If I precook them, as I would like/hope to do for Easter dinner what temp would use to reheat?
Marie
So glad everyone enjoys! To reheat, cover it with foil, and put in a 350-oven for 15-20 min or until heated through. Hope you have a great holiday!
OK, so I tried the potatoes au gratin recipe as a side with some bay scallops with garlic and shallots, the veggie was sugar snap peas… It went very well together and paired nicely with the Chardonnay I served.
I folled the recipe to a T and must say it was indeed delicious. I will use it as my go to recipe for Potatoes au gratin though I may add a bit of celery salt just for a bit of difference.
Over all this recipe was really nice, and well received by my rather persnickety family… Once Upon A Chef has become one of my Go-To websites for trust worthy recipes.
Made these for a dinner party last night and it was amazing. So creamy and flavorful. Everyone loved them.
This is my go to recipe for Au gratin potatoes. I do a mixture of russet and sweet potatoes alternating each layer and use swiss cheese and parm combo. Every Easter, I hope for leftovers, but there are none!
Every recipe from Once Upon a Chef is wonderful, but this is my favorite–and the dish I”m asked to bring whenever we get together with friends. I don’t change a thing. Assembly is easier if you use a mandoline for slicing the potatoes, but be very careful. The recipe does not call for human skin!