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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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Sounds great, but I’d like to cut calories. Could I use 1C heavy cream and 1-1 1/2 C 2% milk?
Hi Sylvia, Unfortunately milk doesn’t work very well in this recipe. While it’s definitely an indulgence, I would stick with the cream.
This au gratin will be my contribution to a dinner for 11 this week and I wanted to know how much I can/should cook it in advance. Hostess has only one oven, so do I cook it entirely at home and ‘reheat’ it there? Or, should I cook it 2/3’s or 3/4′ or ? and finish it at her home? Should I modify the proportions with this caveat in mind? More cream, thinned with some water to help it endure the interruption in cooking?
I tried it for just we two this evening–it was excellent–and I greatly appreciate having a more predictable ‘go to’ than the ones I’ve been doing for the past 20 years.
Thanks very much for your guidance–I’ve only got 48+/- hours until her dinner,
Lynne
Hi Lynne, While this is best made fresh, you can make ahead if necessary. I would fully cook it and then reheat, covered with foil, in a 350 oven for 15-20 min.
I have a large stoneware rectangular baking dish, approximately 13x 9x 2. Would I be able to increase the recipe and use this dish successfully?
Hi Deb, I would think you could probably make 1 1/2 times the recipe and fit it in a 13x 9 x 2. Hope you enjoy it!
Amazing recipe! Tried it yesterday for a Pre-Christmas Dinner with couple of friends and they just love it!!! Cant wait to try it again! Just an advice I used lesssalt cz the cheese and the cream are already salty! Thank you For sharing amazing recipe with usss
After assembling the potatoes au gratin in baking dish can you “hold” it for a coupe hours prior to baking? Want to make this for Christmas dinner and trying to avoid a last minute rush. Many thanks.
Keith, you can assemble this ahead, but you need to cover it tightly with plastic wrap, pressing the wrap directly against the potatoes so they don’t turn color. Hope everyone enjoys!
I was thinking about adding pancetta into this, would you suggest cooking the pancetta separately and then layering when i add the cheese and the cream? the cheese and cream should help the pancetta from overcooking/drying out, correct? also thought about topping off with scallions when it comes out of the oven. what are your thoughts?
Hi Meena, Yes, I would suggest cooking the pancetta before layering it in the gratin. And I think scallions or chives on top of the gratin would be delicious!
This looks absolutely delicious. I will be making this for our Christmas dinner. Can I use a 3 quart dish and do one and a half of the recipe? Thanks in advance.
Yes Mina, you could get away with making 1 1/2 times the recipe and using a 3 quart baking dish. You will likely need to increase the baking time a bit. I’d start checking it after about 1 hour and 20 minutes.
Thank you. Would you suggest using a microplane or traditional grater for the cheese?
Hi Mina, Either will work fine. I use a traditional grater with fine holes.
I made this recipe and while it is quite good, and cooked up very nicely, it came out very salty. I think I’d either reduce the salt to 1/2 tsp or none at all. (Maybe the cheese was saltier than I expected?)
How would these be cooked a day ahead and reheated
Hi Tom, These are best made fresh but you can make ahead if necessary; reheat, covered with foil, in a 350 oven for 15-20 min.
I just wanted to let you know that I was reluctant to make this recipe, as I did not care for Potatoes Au Gratin from my childhood. I was testing this recipe for Thanksgiving, and I must say AMAZING!!!
Thank you so much for sharing such a simple, delicious recipe. I might want to add a slight amount of gooey cheese next time time, but not necessary, as it it perfect just the way it is, such a delicious flavor!