Air Fryer Potatoes Au Gratin
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Air Fryer Potatoes Au Gratin is the reason I fell in love with my air fryer all over again. The layers of thinly sliced potatoes come out perfectly tender, soaked all the way through in a rich Gruyère cream sauce that bubbles up into a golden, slightly crispy top. Pure comfort food that’s ready faster than the oven ever managed.
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I make this side dish for holiday gatherings, Sunday dinners, and potlucks because it feeds a crowd and pairs beautifully with whatever is on the main plate. It’s an easy make-ahead option that always gets compliments. Leftovers keep in the fridge for up to 4 days and reheat beautifully.
Ingredients You’ll Need
You’ll need all the ingredients shown in the photograph below.
How to Make Air Fryer Potatoes Au Gratin with Step-By-Step Instructions
Scroll down for the full recipe card containing a full printable recipe and measurements in both US customary and metric units.
Let me walk you through each step so your air fryer potatoes au gratin come out perfectly golden and creamy every time. If you love cheesy scalloped potatoes, you’re going to love this version with its rich Gruyère cheese sauce and caramelized onions.
Butter the Baking Dish
Start by buttering a 10 × 15 × 2-inch air-fryer-safe baking dish that fits your air fryer basket. Getting the dish well-coated keeps the potato layers from sticking and makes serving so much easier later.
Caramelize the Onions
Melt the butter with a splash of olive oil in a skillet over medium-low heat, then cook the onions for 10 minutes until softened. I use a large nonstick skillet for this because it heats evenly and lets you control the temperature well.
Low and slow is the way to go here. You want them sweet, tender, and golden rather than browned and crispy.
Make the Cream Mixture
In a large bowl, combine the heavy cream, 2 cups of the Gruyère, 1 teaspoon salt, and ½ teaspoon black pepper, then stir in the softened onions. If you’d like to switch things up, sharp cheddar can be a substitute for Gruyère, and you can add a clove of minced garlic or a pinch of garlic powder to the cream mixture for extra depth.
Pre-shredded cheese has coatings that prevent it from melting as smoothly, so freshly grated cheese really does make a difference here. I always use my box grater to grate my cheese fresh from the block.
Layer the Potatoes
Layer the sliced potatoes in the prepared dish, then pour the cream mixture evenly over the top, making sure each thin layer of potato is well coated. Sprinkle the remaining ½ cup of Gruyère over everything, and feel free to scatter some sliced green onions on top before air frying for a pop of color and mild onion flavor.
For even, thin slices that cook through properly, a mandoline slicer is your best friend. It speeds up the prep process and gives you consistent layers throughout the dish.
Air Fry Until Golden and Bubbling
Air fry at 350°F (180°C) for 30 to 40 minutes, or until the potatoes are fork-tender and the top is golden and bubbling. I reach for an instant-read thermometer to confirm that the internal layers are fully cooked.
Every air fryer runs a little differently, so start checking around the 30-minute mark.
Rest Before Serving
Let the dish rest for 10 minutes before serving. I know it’s hard to wait, but resting lets the cream sauce thicken slightly, and the layers settle, so everything holds together when you scoop it.
Serve and Enjoy
Scoop generous portions straight from the dish and serve hot. Enjoy!
If you’re taking it somewhere, cover the dish tightly with foil and transport it in an insulated casserole carrier to keep it warm and protected on the way.
Ingredients
- 4 large russet potatoes peeled and thinly sliced using a mandolin or sharp knife
- 2 cups heavy cream
- 2 ½ cups Gruyère cheese grated and divided
- 1 cup yellow onion halved and thinly sliced crosswise
- 2 tablespoons olive oil
- 3 tablespoons unsalted butter
- Salt and black pepper to taste
Instructions
- Butter a 10 × 15 × 2-inch air-fryer-safe baking dish that fits your air fryer basket.
- Melt the butter with a splash of olive oil in a skillet over medium-low heat. Cook the onions for 10 minutes until softened.2 tablespoons olive oil, 3 tablespoons unsalted butter
- In a large bowl, combine heavy cream, 2 cups Gruyère, 1 teaspoon salt, and ½ teaspoon black pepper. Stir in the onions.2 cups heavy cream, 2 ½ cups Gruyère cheese, 1 cup yellow onion, Salt and black pepper
- Layer the sliced potatoes in the prepared dish and pour the cream mixture evenly over the top. Sprinkle with the remaining ½ cup Gruyère cheese.4 large russet potatoes
- Air fry at 350°F (180°C) for 30–40 minutes, or until the potatoes are fork-tender and the top is golden and bubbling.
- Rest for 10 minutes before serving.
Notes
- Slice the potatoes evenly: Use a mandoline for consistent thickness so every layer cooks at the same rate. Uneven slicing results in some pieces being undercooked while others turn mushy.
- Caramelize the onions low and slow: Don’t rush the onion step. Cooking them for the full 10 minutes over medium-low heat brings out their natural sweetness, adding depth to the dish.
- Grate the Gruyère fresh: Freshly grated cheese melts into the cream far more smoothly than pre-shredded. It’s worth the extra couple of minutes for a silkier sauce.
- Press the layers down before air frying: Once you’ve poured the cream mixture over the potatoes, press the layers gently with the back of a spoon so everything is submerged and the cream reaches all the way through.
- Check early: Air fryers vary, so start checking at the 30-minute mark by pressing a fork through the top layers. You want them to slide through without resistance before you pull the dish out.
- Cool before covering: If you’re planning to store leftovers, let the dish cool uncovered for 20 to 30 minutes before covering and refrigerating. Trapping steam while it’s still hot can make the top layer watery.
Nutrition
How to Store Leftovers
Let the Air Fryer Potatoes Au Gratin cool completely before storing. Transfer leftovers to an airtight container or cover the baking dish tightly with plastic wrap and refrigerate for up to 4 days.
To reheat, cover with foil and warm in a regular oven at 325°F until heated through. If the sauce looks a little thick after refrigeration, stir in a small splash of milk before reheating to loosen it.
For longer storage, freeze portions in a freezer-safe container for up to 2 months. Thaw overnight in the fridge before reheating. The texture of the potatoes may soften slightly after freezing, but the flavor stays just as rich and comforting.
What to Serve With Air Fryer Potatoes Au Gratin
It’s a rich, cheesy side dish, so it pairs beautifully with something light and fresh at dinner. A crisp green salad with a simple lemon vinaigrette cuts right through the richness and balances the plate nicely. Roasted asparagus, steamed green beans, or sautéed spinach all work really well too and round out the meal with color and freshness.
If you want to build a more substantial vegetarian spread, serve it alongside a slice of vegetable quiche, a warm bowl of French onion soup, or some crusty bread to soak up all that extra cream sauce. It also makes a wonderful side for a cheese-and-bread board if you’re entertaining.
More Easy Recipes for You to Try at Home
If you love this, here are more delicious potato recipes you can make right in your air fryer.
