Air Fryer Vegan Broccoli Casserole
Add Preferred SourceWhen I want that creamy casserole comfort, Air Fryer Vegan Broccoli Casserole delivers without heating up my kitchen. The sauce starts simple with mushrooms and garlic, but as everything comes together, it turns richer and creamier than you’d expect, coating every tender broccoli floret. Crispy fried onions on top add perfect crunch, making it the kind of side dish that disappears fast at dinner.
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I make this for weeknight dinners and holiday gatherings because it’s quick, budget-friendly comfort food that feeds a crowd. It’s perfect for Thanksgiving, Christmas, Friendsgiving, and fall and winter potlucks since you can prep it ahead and air-fry just before serving. Leftovers stay creamy in the fridge for 4 days or freeze for up to 3 months.
Ingredients You’ll Need
You’ll need all the ingredients shown in the photograph below.
How to Make Air Fryer Vegan Broccoli Casserole 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.
You’ll have this creamy, crispy casserole ready in no time with just a few simple steps.
Blanch the Broccoli
Bring a large pot of salted water to a boil, then add your broccoli florets and cook them for 4 to 5 minutes until they turn into tender broccoli while staying bright green. Drain them in this stainless steel colander and set them aside while you make the sauce, as this quick blanching step helps the broccoli cook evenly in the air fryer without turning mushy.
Cook the Mushrooms and Garlic
Heat olive oil in a large nonstick skillet over medium heat. Toss in the sliced mushrooms and let them cook for 6 to 7 minutes without stirring too much, allowing them to brown nicely for the best texture. I use this nonstick skillet because it heats evenly and lets the mushrooms brown beautifully without sticking, making the whole cooking process so much easier.
Once they’re golden, stir in the minced garlic and cook for another minute until fragrant, letting the mushrooms deepen into a meaty, savory base for your sauce. A garlic press is a must-have because it minces the cloves in seconds and keeps my hands from getting garlicky.
Make the Creamy Sauce
Sprinkle the flour over the mushrooms and stir everything together until the mushrooms are coated. Slowly whisk in the vegetable broth and plant-based milk so they blend into a smooth mixture with a creamy flavor.
I use a silicone whisk for this step because it keeps the sauce silky smooth and never scratches my pans. Add the nutritional yeast, soy sauce, onion powder, salt, and black pepper, then let everything simmer for 5 to 7 minutes, stirring occasionally as the sauce thickens and turns beautifully creamy.
Combine and Transfer to Air Fryer
Grab an air fryer-safe baking dish that fits inside your air fryer basket. Add the blanched broccoli and pour the mushroom sauce over the top, stirring until every floret is coated in that creamy goodness.
Make sure everything is spread out evenly so it heats through properly. I usually reach for my favorite baking dish here because it fits perfectly in my air fryer and consistently gives me even heating, which is key for getting the creamy, cozy casserole texture every time.
Air Fry Until Bubbly
Place the dish in your air fryer and cook at 350°F (175°C) for 10 to 15 minutes, or until the casserole is hot and bubbly around the edges. During this cooking time, you’ll see the sauce start to bubble and thicken even more as it heats.
Add the Crispy Topping
Sprinkle the crispy fried onions evenly over the top of your casserole, making sure to cover the entire surface so every serving gets the crunchy topping. Air fry for another 3 to 5 minutes, or until the onions turn golden brown and crispy.
Watch them closely during the last couple of minutes so they don’t burn. Let the casserole rest for a few minutes before serving so the sauce can settle and thicken slightly. Serve and enjoy!
If you’re bringing this dish to a potluck or family gathering, slipping your baking dish into an insulated casserole carrier like this one keeps it hot for hours and prevents any messy spills during the drive.
Equipment
Ingredients
- 1 pound fresh broccoli florets trimmed
- 2 tablespoons olive oil
- 8 ounces mushrooms sliced
- 3 cloves garlic minced
- 2 tablespoons all-purpose flour
- 1 cup vegetable broth
- 1 cup unsweetened plant-based milk
- 2 tablespoons nutritional yeast
- 1 tablespoon soy sauce
- 1 teaspoon onion powder
- Salt and black pepper to taste
- 1 ½ cups crispy fried onions store-bought or homemade
Instructions
- Bring a large pot of salted water to a boil. Add the broccoli florets and cook for 4 to 5 minutes, until just tender. Drain and set aside.1 pound fresh broccoli florets
- Heat olive oil in a large skillet over medium heat. Add the sliced mushrooms and cook for 6 to 7 minutes, until browned. Stir in the minced garlic and cook for another 1 minute.2 tablespoons olive oil, 8 ounces mushrooms, 3 cloves garlic
- Sprinkle the flour over the mushrooms and stir well to coat. Gradually whisk in the vegetable broth and plant-based milk until smooth.2 tablespoons all-purpose flour, 1 cup vegetable broth, 1 cup unsweetened plant-based milk
- Add the nutritional yeast, soy sauce, onion powder, salt, and black pepper. Simmer for 5 to 7 minutes, stirring occasionally, until the sauce thickens.2 tablespoons nutritional yeast, 1 tablespoon soy sauce, 1 teaspoon onion powder, Salt and black pepper
- In a baking dish that fits your air fryer, combine the blanched broccoli and mushroom sauce. Stir until evenly coated.
- Place the dish in the air fryer and cook at 350°F (175°C) for 10 to 15 minutes, or until hot and bubbly.
- Sprinkle the crispy fried onions evenly over the top. Air fry for another 3 to 5 minutes, or until the topping is golden and crisp.1 ½ cups crispy fried onions
- Let it rest for a few minutes before serving warm.
Notes
- Don’t overcook the broccoli: Blanch it for just 4 to 5 minutes so it stays slightly firm, since it’ll cook more in the air fryer, and you don’t want mushy broccoli.
- Brown the mushrooms properly: Let them sit in the pan without stirring too much so they release their moisture and get that golden, caramelized flavor instead of steaming.
- Whisk out the lumps: When you add the flour, make sure to whisk constantly as you pour in the liquids so your sauce stays smooth and doesn’t get clumpy.
- Use the right dish size: Your baking dish should fit comfortably in your air fryer basket with a little space around it for air circulation; otherwise, the casserole won’t heat evenly.
- Watch the topping closely: Crispy fried onions can go from golden to burnt quickly, so keep an eye on them during the last few minutes of cooking.
- Flash freeze for meal prep: If you’re freezing portions, spread them on a baking sheet and freeze for 1 hour before transferring to containers so the sauce doesn’t stick together in one big clump.
Nutrition
How to Store Leftovers
Let the casserole cool completely before storing it in an airtight container in the fridge for up to 4 days. The sauce may thicken as it sits, so just stir in a splash of plant-based milk when you reheat it. I always use an airtight glass container like this one because it seals everything in so well that the casserole stays fresh for days, and it makes reheating a breeze without losing any of that creamy texture.
For longer storage, transfer portions to freezer-safe containers and freeze for up to 3 months. Seal the dish well by wrapping it in BPA-free plastic wrap and then a layer of aluminum foil, or portion it out into individual containers for easier storing and reheating. Thaw overnight in the fridge before reheating.
To reheat, pop it back in the air fryer at 320°F for 5 to 7 minutes, or microwave individual portions for 1 to 2 minutes, or warm the entire dish in a 350°F oven for about 15 minutes until heated through. The onion topping might lose some crispiness after storage, so feel free to add fresh crispy onions on top after reheating for extra crunch.
What to Serve With Air Fryer Vegan Broccoli Casserole
This casserole pairs beautifully with baked tofu, grilled tempeh, or lentil loaf for a complete meal. I also love serving it alongside mashed potatoes, wild rice pilaf, or quinoa when I want something a bit heartier. A simple green salad with lemon vinaigrette helps balance the richness without competing with the creamy mushroom flavors.
For holiday dinners, it fits right in next to stuffing, cranberry sauce, and dinner rolls at Thanksgiving or Christmas spreads. A bright side like harvest salad adds fresh, tangy contrast that keeps the plate from feeling too heavy. You can also serve it as a main dish with crusty bread on the side for a cozy dinner that feels really satisfying.
More Easy Recipes for You to Try at Home
You’ll love these other vegan air fryer casseroles perfect for holidays and weeknight dinners.
