Air Fryer Green Bean Casserole

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This air fryer green bean casserole is one of those recipes that makes holiday cooking so much easier. You get all the creamy, savory goodness of the classic dish — crispy onions, tender green beans, rich mushroom sauce — but without heating up your oven for an hour. I started making this version three Thanksgivings ago when my oven was packed with turkey and sides, and now I honestly prefer it this way. The air fryer gives you better texture control and frees up precious oven space when you need it most.

Ingredients

For the casserole:

• 1 pound fresh green beans, trimmed and cut into 2-inch pieces
• 8 ounces mushrooms, sliced
• 2 tablespoons butter
• 2 cloves garlic, minced
• 2 tablespoons all-purpose flour
• 1 cup whole milk
• ½ cup heavy cream
• ½ cup chicken broth (or vegetable broth)
• 1 teaspoon soy sauce
• ½ teaspoon onion powder
• ½ teaspoon black pepper
• ¼ teaspoon salt
• 1 cup shredded cheddar cheese
• 1½ cups crispy fried onions, divided

Substitution notes: You can use frozen green beans if fresh aren’t available — just thaw and pat them completely dry first. For a dairy-free version, swap the butter for olive oil and use cashew cream instead of milk and heavy cream. If you don’t have crispy fried onions, panko breadcrumbs tossed with a little melted butter work as a crunchy topping.

How to Make Air Fryer Green Bean Casserole

This recipe comes together in simple layers — you’ll build the sauce, combine everything, and let the air fryer work its magic.

1. Blanch the green beans. Bring a pot of salted water to a boil, add the green beans, and cook for 4 minutes until bright green and slightly tender, then drain and set aside.
2. Sauté the mushrooms. In a large skillet over medium-high heat, melt the butter and cook the sliced mushrooms for 5 minutes until they release their moisture and turn golden brown, then add the minced garlic and cook for 1 minute more.
3. Make the cream sauce. Sprinkle the flour over the mushrooms and stir constantly for 1 minute, then slowly pour in the milk, heavy cream, and chicken broth while whisking to create a smooth sauce.
4. Season and thicken. Add the soy sauce, onion powder, black pepper, and salt, then simmer for 3 minutes stirring frequently until the sauce thickens enough to coat the back of a spoon.
5. Combine everything. Remove from heat and stir in the shredded cheddar cheese until melted, then fold in the blanched green beans and 1 cup of the crispy fried onions until everything is evenly coated.
6. Transfer to air fryer dish. Spray a 7-inch or 8-inch round baking dish (that fits in your air fryer) with cooking spray, then pour the green bean mixture into the dish and spread it evenly.
7. Air fry the casserole. Place the dish in the air fryer basket and cook at 350°F (175°C) for 12 minutes until the sauce is bubbling around the edges and the top is lightly golden.
8. Add final topping and crisp. Sprinkle the remaining ½ cup of crispy fried onions over the top and air fry for an additional 3 minutes at 350°F (175°C) until the onions are deeply golden and extra crunchy.

Recipe Variations

What to Serve With Air Fryer Green Bean Casserole

This casserole is the ultimate holiday side, but it works beautifully year-round too. Serve it alongside air fryer turkey breast for a complete Thanksgiving spread that never touches your oven. It’s also perfect with air fryer pork chops or a simple roasted chicken for Sunday dinner.

For a full comfort food meal, pair it with air fryer mashed potato cakes and glazed carrots. The casserole’s creamy richness balances beautifully with lighter, brighter sides like a crisp apple walnut salad or roasted Brussels sprouts.

If you’re serving this at a potluck or holiday gathering, it travels well in the baking dish. Just reheat it in the air fryer for 5 minutes at 320°F (160°C) before serving to bring back that crispy top.

Storage & Reheating

Refrigerator: Store leftover air fryer green bean casserole in an airtight container in the fridge for up to 4 days. The fried onions will soften as it sits, but you can refresh them when reheating.

Freezer: This casserole freezes well for up to 2 months. Let it cool completely, then wrap the entire dish tightly in plastic wrap and aluminum foil. Thaw overnight in the refrigerator before reheating.

Reheating in the air fryer: Place the casserole in your air fryer at 320°F (160°C) for 8 minutes until heated through and bubbling. If you want to restore the crispy topping, sprinkle fresh fried onions on top and air fry for an additional 2 minutes at 350°F (175°C). You can also reheat individual portions in small ramekins at the same temperature for 5 minutes.

Frequently Asked Questions

Can I make air fryer green bean casserole ahead of time?

Yes! Assemble the entire casserole up to 24 hours in advance, but don’t add the final topping of fried onions yet. Cover tightly with foil and refrigerate. When you’re ready to cook, let it sit at room temperature for 15 minutes, then air fry as directed. Add the onion topping during the last 3 minutes of cooking so they stay crispy.

What size air fryer do I need for this recipe?

You’ll need at least a 5-quart air fryer to fit a 7-inch or 8-inch round baking dish. If you have a smaller air fryer, divide the casserole between two smaller dishes and cook them in batches. For larger air fryers (8-quart or bigger), you can use an 8-inch square dish and the cooking time stays the same.

Can I use canned green beans instead of fresh?

You can, but the texture won’t be quite as good. Canned green beans are already fully cooked and tend to get mushy. If you do use them, drain them very well, skip the blanching step entirely, and reduce the air frying time by 2 minutes. Frozen green beans (thawed and dried) work much better than canned if fresh aren’t available.

Why is my casserole watery?

This usually happens if the green beans weren’t dried properly after blanching, or if you used frozen beans without thawing and patting them completely dry first. Make sure your cream sauce has thickened properly in step 4 before adding the beans — it should coat the back of a spoon. If your casserole looks too liquidy before air frying, let it sit for 5 minutes so the beans can absorb some of the sauce.

Can I make this casserole dairy-free?

Absolutely. Replace the butter with olive oil or vegan butter, use unsweetened cashew cream or oat cream instead of the milk and heavy cream, and skip the cheese or use a dairy-free alternative. The sauce won’t be quite as rich, but you can add an extra tablespoon of flour to help it thicken. Nutritional yeast adds a nice savory depth if you’re skipping the cheese entirely.