Cheesy Potatoes Au Gratin
I love potatoes in every possible form. Mashed, baked, fried, roasted—I’ve truly never met a potato I didn’t like. But when you start adding lots of cheese and butter, something magical happens.
These cheesy potatoes au gratin are everything I want in a comfort food side dish: thinly sliced Yukon gold potatoes tucked into a velvety, garlicky cream sauce and baked under a blanket of bubbling, golden cheese. This is the kind of recipe that feels fancy enough for holidays and Sunday dinners, but still uses simple, down-to-earth ingredients you probably already have on hand.
Serve this in the center of the table and watch everyone go quiet for that first bite.
And while you are here, check out these other great recipes!
Garlic Cheddar Mashed Potatoes
The Ultimate Green Bean Casserole
Creamy Stovetop Mac and Cheese
Table of contents
What Is the Difference Between Potatoes Au Gratin and Scalloped Potatoes?
People use the terms potatoes au gratin and scalloped potatoes interchangeably, but they’re technically a little different:
- Scalloped potatoesTraditionally, scalloped potatoes are sliced potatoes baked in a creamy sauce (usually made with milk or cream, butter, and sometimes a roux) and seasoned simply with salt, pepper, and maybe some herbs. Classic scalloped potatoes do not always include cheese in the sauce or on top.
- Potatoes au gratinPotatoes au gratin usually include cheese—both in the sauce and baked on top. “Au gratin” refers to that browned, crisp, cheesy topping that forms as it bakes. Au gratin potatoes are often a little richer and more indulgent thanks to multiple cheeses.
This recipe definitely falls in the cheesy potatoes au gratin camp: we’re talking a creamy, three-cheese sauce with cheddar, smoked Gouda, and Boursin, plus an extra layer of cheese melted on top until it’s perfectly golden and bubbly.
What You’ll Love About This Cheesy Potatoes Au Gratin Recipe
- Ultra creamy and extra cheesy – Three cheeses in the sauce and more on top means every bite is rich, melty, and packed with flavor.
- Perfect for holidays and special occasions – This is a show-stopper side dish that looks gorgeous coming out of the oven and tastes like pure comfort.
- Simple, everyday ingredients – Even though it tastes fancy, you’re mostly working with potatoes, half-and-half, butter, and cheese. Nothing complicated.
- ** Hands-off baking time** – Once you assemble the potatoes and sauce, the oven does the heavy lifting.
- Family-friendly comfort food – Cheesy potatoes au gratin are one of those sides that everybody gets excited about, from picky eaters to grown-ups.
Ingredients for Cheesy Potatoes Au Gratin
- 4 tablespoons butter – Helps sauté the onions, builds the roux for the sauce, and adds rich, buttery flavor to every bite.
- 1 small onion, finely diced – Cooks down into the sauce and adds a subtle sweetness and depth that keeps the flavor from being one-note.
- 4–5 cloves garlic, minced – Brings that savory, garlicky flavor that pairs perfectly with the cheese and potatoes.
- 1/4 cup all-purpose flour – Whisked into the butter to create a roux, which thickens the creamy sauce so it clings to all the potato slices.
- 4 cups half-and-half (room temperature) – Makes the sauce luxuriously creamy without going quite as heavy as straight cream. Using it at room temperature helps prevent the sauce from seizing or getting lumpy.
- 1 tablespoon dried herbs de Provence – Adds a fragrant blend of herbs (like thyme, rosemary, oregano, etc.) that gives the cheesy potatoes au gratin a little something extra and makes it taste like it’s been simmering all day.
- 1 teaspoon dried mustard powder – You don’t really taste “mustard,” but it sharpens and brightens the cheese sauce, making the flavors pop.
- 1/2 teaspoon black pepper – Adds gentle warmth and balances the richness of the cream and cheese.
- 1 teaspoon salt (plus more for the potato layers) – Seasons the sauce, but you’ll also salt each layer of potatoes so the whole dish is flavorful from top to bottom.
- 1 cup freshly grated sharp cheddar cheese (for the sauce) – Gives the sauce that classic, sharp cheesy flavor we all love in au gratin potatoes.
- 1 cup freshly grated smoked Gouda (for the sauce) – Adds creaminess and a subtle smoky flavor that makes these potatoes feel restaurant-level special.
- 1 (5.3 oz) package Boursin garlic & herb cheese – Melts into the sauce and brings even more garlic, herbs, and tangy creaminess. It’s a big part of what makes the sauce so velvety and flavorful.
- 3 pounds Yukon gold potatoes, thinly sliced (mandolin recommended) – Yukon golds stay tender and creamy without falling apart. Slicing them thinly helps them cook evenly and soak up all that cheesy sauce.
- Butter, for greasing the baking dish – Helps prevent sticking and adds just a touch more buttery goodness to the edges of the potatoes.
- 1 cup freshly grated sharp cheddar cheese (for topping) – Melts into a golden, bubbly top layer of cheese.
- 1 cup freshly grated smoked Gouda (for topping) – Combines with the cheddar to create that beautiful, cheesy “au gratin” crust on top.
Step-by-Step Instructions
First, preheat your oven to 375°F. Next, place a large skillet over medium heat and melt 4 tablespoons of butter. Add the finely diced onion and cook for about 5 minutes, stirring occasionally, until the onion is soft and translucent.
After the onions have softened, stir in the 4–5 minced garlic cloves and cook for about 1 minute, just until fragrant. Then, whisk in the 1/4 cup of flour, making sure it coats the onions and garlic. Let this cook for 1–2 minutes, whisking often—this step cooks out the raw flour taste and builds the base of your creamy au gratin sauce.
Now, reduce the heat slightly and slowly pour in the 4 cups of room temperature half-and-half, about 1 cup at a time, whisking constantly. Continue cooking and whisking until the mixture thickens into a smooth, creamy sauce. This is what will coat every slice of potato in your cheesy potatoes au gratin. Once the sauce has thickened, stir in the herbs de Provence, dried mustard, black pepper, and salt. Taste and adjust the seasoning if needed. This is your chance to build flavor before the cheese goes in.
The Sauce
Turn the heat down to low. Gradually add 1 cup sharp cheddar, 1 cup smoked Gouda, and the 5.3 oz Boursin garlic & herb cheese, stirring constantly until everything is melted and the sauce is velvety and smooth. At this point, your cheesy au gratin sauce should be thick, glossy, and absolutely irresistible.
Grease an 11-inch pie plate (or a similarly sized baking dish) generously with butter. Using a mandolin, thinly slice your 3 pounds of Yukon gold potatoes.
Tip: thinly sliced Yukon gold potatoes are key for tender, creamy cheesy potatoes au gratin, but you can use russets if that is all you have!
Lastly
Now it’s time to assemble. Place about one-third of the sliced potatoes in an even layer in the buttered baking dish. Lightly sprinkle with salt to season that layer. Then pour about one-third of the cheese sauce evenly over the top, making sure it seeps down between the slices.
Repeat this process two more times—potatoes, salt, sauce—until you’ve used all of the potatoes and all of the sauce.
Next, cover the dish tightly with foil and place it on a foil-lined baking sheet or drip pan (this recipe can bubble over just a bit). Bake at 375°F for about 1 hour, or until the potatoes are mostly tender when pierced with a knife.
Then, carefully remove the foil and sprinkle the top with 1 cup freshly grated sharp cheddar and 1 cup freshly grated smoked Gouda. Return the cheesy potatoes au gratin to the oven and bake uncovered for another 20–30 minutes, or until the top is golden brown, bubbly, and slightly crisp around the edges. Finally, remove the dish from the oven and let it rest for 10–15 minutes before serving. This resting time allows the cheesy sauce to thicken and set so your potatoes au gratin slice beautifully instead of running all over the plate.
Garnish with freshly chopped parsley if desired.
Tips for Success
- Use a mandolin for even slices. Even thickness ensures the potatoes cook at the same rate and become perfectly tender in the center while the top gets golden and bubbly.
- Salt every layer of potatoes. Don’t rely on the sauce alone for seasoning. Lightly salting each layer of potatoes as you build the dish gives you flavor all the way through.
- Use room temperature half-and-half. Cold dairy can cause the sauce to seize or take longer to thicken. Room temperature half-and-half gives you a smoother, creamier sauce.
- Freshly grated cheese melts better. Pre-shredded cheese is convenient, but it often contains anti-caking agents that can make the sauce grainy. Freshly grated cheddar and Gouda give you the best melt and texture.
- Let it rest before serving. Ten to fifteen minutes of resting time is key. It helps the sauce thicken up so you get beautiful, creamy slices instead of a soupy mess.
If you do make this recipe, please leave a comment and a rating! I love hearing from you and it helps so much! Thank you!
Cheesy Potatoes Au Gratin
Ingredients
For the Cheese Sauce
- 4 tbsp Salted Butter
- 1 Yellow Onion, Diced
- 4-5 Garlic Cloves, minced
- 1/4 Cup All Purpose Flour
- 4 Cups Half and Half, room temperature
- 1 tbsp Herbs De Provence
- 1 tsp Dried Mustard Powder
- 1 tsp Salt plus more for the potatoes when layering
- 1/2 tsp Black Pepper
- 1 Cup Freshly Shredded Sharp Cheddar Cheese
- 1 Cup Freshly Shredded Smoked Gouda Cheese
- 1 (5.3 oz) Boursin Garlic and Herb Cheese
For the Potatoes and Topping
- Butter for greasing the baking dish, or cooking spray works too
- 3 lbs Yukon Gold Potatoes, thinly sliced mandolin recommended
- 1 Cup Freshly Shredded Sharp Cheddar Cheese
- 1 Cup Freshly Shredded Gouda Cheese
Instructions
- Preheat your oven to 375°F. Generously butter an 11-inch pie plate or similar baking dish. Place the dish on a baking sheet or drip pan to catch any overflow.
- In a large skillet over medium heat, melt the 4 tablespoons of butter. Add the diced onion and cook for about 5 minutes, until softened. Stir in the minced garlic and cook for another minute, until fragrant.
- Whisk in the 1/4 cup flour and cook for 1–2 minutes, stirring often, to cook out the raw flour taste.
- Slowly pour in the 4 cups of half-and-half, about 1 cup at a time, whisking constantly. Continue cooking and whisking until the sauce thickens and is smooth and creamy.
- Stir in the herbs de Provence, dried mustard, black pepper, and 1 teaspoon salt. Reduce the heat to low and add 1 cup cheddar, 1 cup smoked Gouda, and the Boursin, stirring until all the cheese is melted and the sauce is smooth.
- Using a mandolin, thinly slice the 3 pounds of Yukon gold potatoes. Arrange about one-third of the slices in an even layer in the buttered dish. Lightly sprinkle with salt, then pour about one-third of the cheese sauce over the top. Repeat with two more layers of potatoes, salt, and sauce, ending with sauce.
- Cover the dish tightly with foil and bake at 375°F for about 1 hour, or until the potatoes are mostly tender when pierced with a knife.
- Remove the foil and sprinkle the top with the remaining 1 cup cheddar and 1 cup smoked Gouda. Return to the oven and bake uncovered for 20–30 minutes, or until the top is golden brown, bubbly, and slightly crisp around the edges.
- Remove from the oven and let it rest for 10–15 minutes before serving, which allows the sauce to thicken and set.
Notes
- Salt each layer: For the best flavor, lightly salt each layer of potatoes as you build the dish. If you only season the sauce, the potatoes in the middle can taste a little flat. Salting the layers ensures every bite of your cheesy potatoes au gratin is well seasoned from top to bottom.
- Let it rest before serving: It’s tempting to dig in right away, but letting the potatoes rest for 10–15 minutes is important. The sauce thickens and sets as it cools slightly, so the potatoes slice and serve more cleanly and the texture stays nice and creamy instead of soupy.
- Dish size and drip pan: An 11-inch pie plate will hold this recipe, but it will be quite full and may bubble over a bit. Place it on a baking sheet or drip pan to keep your oven clean, or use a slightly larger baking dish if you prefer more wiggle room.
- Make-ahead: You can assemble the potatoes and cheese sauce in the dish, cover tightly with foil, and refrigerate for up to 1–2 days before baking. Let it sit at room temperature for about 20–30 minutes, then bake as directed (adding a little extra time if needed).
- Leftovers: Store leftovers in an airtight container in the fridge for 3–4 days. Reheat in the microwave or in a 325°F oven (covered with foil) until hot. If needed, add a splash of half-and-half before reheating to keep everything creamy.
