This Au Gratin Potatoes Recipe features thinly sliced golden potatoes layered in a rich, creamy, and cheesy sauce. It’s a side dish that’s always a hit!
author’s note
The Side Dish That Stole Thanksgiving!
Last year, I was assigned potatoes and a few other sides for my family’s Thanksgiving. One of them was potatoes, and I knew I didn’t want to show up with anything boring. I wanted to make the best Au Gratin Potatoes—super creamy, extra cheesy, and full of flavor.
So I started testing. I tried different potatoes, cheese combos, and bake times until I finally nailed it. The magic combo? Thinly sliced Yukon Golds, fresh thyme, and a mix of Cheddar, Gruyère, and Parmesan. Pure comfort food perfection.
When I brought them to Thanksgiving, my family loved them. They all wanted the recipe, and now these are the potatoes I’m always in charge of bringing.
Ingredients
| Ingredient | Swaps or Tips |
|---|---|
| Yukon Gold Potatoes | Creamy and hold their shape well. Russets work too, just slice a little thinner. |
| Butter & Flour | Makes the sauce thick and silky. Use gluten-free flour or a 1:1 GF blend if needed. |
| Whole Milk | Adds creaminess. 2% works fine, but skip skim or plant-based milk for this au gratin potatoes recipe. |
| Cheddar & Gruyère | The flavor combo is everything. Use Swiss, Emmental, or Comté if you can’t find Gruyère. |
| Parmesan (fresh grated) | Adds sharp flavor and helps brown the top. Skip pre-grated for the best melt. |
| Garlic & Thyme | Bring in fresh flavor. Swap thyme for rosemary, parsley, or chives. |
How To Make Au Gratin Potatoes Recipe
- Preheat oven: Set to 350°F and grease a 9×9-inch baking dish.
- Slice potatoes: Peel and slice thinly.
- Sauce: Melt butter, cook garlic, whisk in flour, then add milk. Boil, thicken, and stir in Cheddar.
- Layer potatoes: Layer potatoes, Gruyère, and thyme in the pan.
- Bake: Cover with foil, bake for 1 hour 15 minutes, then check tenderness.
- Add Parmesan and bake: Sprinkle Parmesan, bake uncovered 10–15 minutes. Let rest before serving.
Quick Tip
These prep tools make the time fly!
- Sharp peeler
- Mandoline slicer
Set the Mandoline slicer to 1/8-inch thickness to get 6 cups of potatoes.
How To Make Ahead Of Time
Assemble and bake. Let cool with foil on, then add cheese, cover with plastic wrap, and refrigerate.
To serve, let sit at room temp for 1 hour. Cover with foil and bake at 350°F for 20–30 minutes. Uncover and bake another 10–15 minutes, until golden and bubbly.
More Potato Recipes To Love:
Potatoes
Cheesy Potatoes
Side Dishes
Crispy Roasted Potatoes Recipe
Potatoes
Creamed Potatoes
Appetizers
Smashed Potatoes Recipe
Au Gratin Potatoes Recipe
Video
Equipment
- 9 x 9-inch baking pan
- Large pot nonstick
Ingredients
- Cooking spray
- 6 packed cups gold potatoes 2 pounds, see note 1
- 3 tablespoons unsalted butter
- 2 teaspoons minced garlic 2 cloves
- 3 tablespoons flour
- Salt and pepper
- 2 cups milk see note 2
- 1 cup shredded sharp Cheddar cheese 3 ounces
- 1 cup shredded Gruyère cheese or more Cheddar, 3 ounces, divided
- 1/2 cup freshly grated Parmesan cheese see note 3
- 2 teaspoons fresh thyme or 1/4 teaspoon dried, optional
Instructions
- Preheat oven to 350°F. Grease a 9×9-inch (or 2-quart) baking pan with cooking spray and set aside.
- Peel and thinly slice potatoes (1/8-inch thick). I use a mandolin slicer for speed and accuracy (see note 1). Measure 6 tightly packed cups of sliced potatoes.
- In a large nonstick pot, melt butter over low heat. Add garlic and sauté for 1 minute until fragrant. Stir in flour and whisk constantly for 1 minute until smooth (avoid browning). Gradually whisk in 1 cup of milk until smooth. Increase heat to medium-high and gradually add the second cup of milk. Stir occasionally until the mixture boils. Season with salt and pepper (I use 1 teaspoon salt and 1/4 teaspoon pepper).
- Once boiling, reduce heat to medium-low and stir constantly for 2 minutes until the sauce thickens (see note 4). Remove from heat and let cool for 2 minutes. Stir in Cheddar cheese, a handful at a time, until melted and smooth. Add the sliced potatoes and stir to coat.
- Assemble the dish by layering 1/3 of the potatoes in the prepared pan, then sprinkle in 1/2 cup Gruyere cheese and 1/3 of the fresh thyme. In the same pan, repeat with another 1/3 of the potatoes, the remaining 1/2 cup Gruyere, and 1/3 thyme. Finish with the remaining potatoes and thyme.
- Cover the pan with foil and bake for 1 hour 15 minutes. Remove the foil and check for tenderness by piercing the potatoes with a knife. If not tender, bake a few more minutes and check again. Once tender, sprinkle 1/2 cup Parmesan cheese on top.
- Bake uncovered for another 10–15 minutes or until golden and bubbly. For extra color, broil for 1 minute at the end. Let stand for 5–10 minutes before serving to allow the sauce to thicken.
Recipe Notes
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
What To Serve With Au Gratin Potatoes Recipe:
- For holidays, pair with Crockpot Turkey Breast, Sweet Potato Casserole, Thanksgiving Salad, and no-knead Dinner Rolls.
- For Easter, serve with Deviled Eggs, Asparagus Salad, Roasted Vegetables, and Drop Biscuits.
- For everyday dinners, enjoy with Blackened Chicken, Turkey Meatloaf, or Lemon Parmesan Chicken.
Variations
- Need more oven space? Try my Crockpot Au Gratin Potatoes instead!
- Want something fun and different? Try individual size potato stacks.
The directions for the x2 did not match the quantity called for in the ingredients section. The directions told me to add 2 cups of milk, but I had prepared 4 cups and. I had to guess when to add the sauce. It did not say when to pour in the sauce either.
The directions don’t get doubled only the quantities so you’ll need to adjust that in the directions. The sauce gets mixed with the potatoes in step 4. It reads: “Once boiling, reduce heat to medium-low and stir constantly for 2 minutes until the sauce thickens (see note 4). Remove from heat and let cool for 2 minutes. Stir in Cheddar cheese, a handful at a time, until melted and smooth. Add the sliced potatoes and stir to coat.”
As Chelsea’s sister and employee I have made and LOVED this recipe! They are always a hit!
Hi, I have three questions. 1) If I wanted to add onions to this recipe how would I go about doing that? Should I sauté them in butter before I add the garlic? Do I need to add more butter to the recipe in order to do that or should I stick to the amount of butter that is called in the recipe) 2) Does making this dish ahead of time, putting it in the fridge and then reheating it the next day change the texture or taste of the dish vs making it and serving it the same day? Which way is better? And then 3) if I needed to triple this recipe should I make it all together in the same dish or use separate dishes? Will this change the time it takes to cook? I’m so excited to try this recipe, it looks amazing! I’m sorry for all the questions! I have little to no experience cooking and this is my first time cooking for 22 people and I’m a little nervous lol any help is much appreciated 🙂
Hi! I’m so glad you’re making this—what a great dish for a crowd! And your questions are totally valid. Here’s the breakdown:
1) Adding onions
Yes, you can! Dice 1 small yellow onion and sauté it with the butter over low heat until soft (about 6–8 minutes), then add the garlic and continue the recipe. No need to add extra butter—the 3 tablespoons is enough.
2) Making ahead vs. fresh
This dish is best fresh—creamy sauce, crispy top. But you can make it ahead and reheat:
Cool, cover, and refrigerate.
Reheat covered at 350°F for 25–30 minutes, then uncover to crisp the top.
Even better: assemble it ahead and bake fresh the day of for the best texture.
3) Tripling the recipe
For 22 people, triple the recipe but use 3 separate 9×9 pans (or 2-quart equivalents). Don’t combine in one large dish—it won’t cook evenly.
Bake all at once, rotating halfway through. Time should be about the same—just check for tenderness before uncovering.
You’ve got this! So excited for you to try it—let me know if you have any other questions!
I am going to make these potatoes for Thanksgiving dinner. A bit confused on directions. It read layer 1/3 of potatoes with 1/2 cup of guyre cheese and then repeat. If you 2x’s recipe it call for 2 cups of cheese. So I assume I add 1 cup of cheese on each layer. I hope you see this and have time to respond. Thanks. By the way all your recipes are the very best.
Our family really loves potatoes with the skins on. Do you think this would be a problem? Can’t wait to try your recipe for the upcoming holidays!
With gold potatoes I don’t see this being a problem! 🙂 Enjoy I hope you love whatever you try!
Thanks SO much for responding – we’ve always loved your recipes, and can’t wait to try this one soon! Xoxo B
Question: I see instructions for make ahead and refrigerate…do you think it’d work to make ahead, cover the same way and freeze, then thaw before baking? They look amazing, Chelsea!
Honestly I’m not sure! I’m so sorry Cathy! I’ve never tried freezing this recipe!