This Vegan Green Bean Casserole is creamy and savory with a classic fried onion topping. It comes together quickly and can even be prepped in advance. It’s a family favorite holiday dish gone vegan that tastes just as delicious and comforting as you remember.
While green bean casserole is a traditional Thanksgiving side dish, it’s easy enough to be enjoyed any time of year. If you can’t find fried onions during the other months, feel free to use Panko bread crumbs instead.
Ingredients you need
Ingredients notes and substitutions
Green beans ~ Personally, I think frozen green beans are the way to go for a casserole. They’re inexpensive, always available, and do not need to be cooked before adding them to the dish.
Do make sure to thaw them completely and then drain them well so they don’t release water while baking and make the casserole watery.
You can use fresh green beans if you prefer. Wash them and trim the ends, blanch them for 2 to 3 minutes, place them in an ice bath, and then drain really well.
Mushrooms ~ Traditional green bean casserole is made with cream of mushroom soup, but we are using real mushrooms in this vegan recipe. I use white button mushrooms, but shiitake mushrooms or cremini mushrooms may be used instead.
I like to finely dice the mushrooms, just like you’d find in the cream of mushroom soup, but you can add thicker slices if you like.
Aromatics ~ Onion and garlic bring flavor!
Seasonings ~ Salt, pepper, and nutritional yeast (for a savory, somewhat cheesy flavor) is all you need for seasoning.
I like to also add a tablespoon of mellow white miso paste for a rich, umami taste. This is optional.
Milk ~ I typically use unsweetened, plain almond milk. It’s always on my plant-based grocery list and is a staple in my kitchen. Whatever unsweetened non-dairy milk you have on hand should work, like oat milk, soy milk, cashew milk, etc.
Flour ~ Flour is going to help thicken the creamy mushroom sauce. All-purpose flour works great, but you can use a gluten-free all-purpose flour if needed.
Butter ~ I use vegan butter to sauté because the smell of onions frying in butter remind me of my grandparents house during the holidays and it brings back all the feels. You can use olive oil instead if you wish.
Topping ~ Fried onions are typical on a green bean casserole. They’re so delicious, why mess with tradition?! French’s Fried Onions and Trader Joe’s Fried Onion Pieces are both plant-based.
I also found Natural Earth brand on Amazon that happens to be vegan and gluten-free.
You can also use breadcrumbs, Panko or regular, if that’s what you have. Gluten-free breadcrumbs can be found in most stores these days, too.
How to make the recipe
Please scroll down to the recipe card for exact ingredient measurements and instructions.
Sauté the onions in vegan butter until soft and translucent. Add the salt and pepper and stir.
Add the diced mushrooms and garlic and sauté until the mushrooms have released their moisture.
Sprinkle the flour over the top and stir well until no white flour is visible.
Slowly pour in the milk, whisking continuously so the flour doesn’t clump. A flat whisk works great for this!
Bring to a boil, then decrease the heat to medium-low and simmer until thickened. Add the nutritional yeast and miso paste, if using.
Add the defrosted and drained green beans and stir well to coat.
Pour into a baking dish.
Top with crunchy fried onions.
Bake until the topping is golden and the middle is hot and bubbly.
Storage and freezing
Prep ahead: The casserole may be prepped and assembled a day in advance. However, do not add the fried onion topping until you are ready to bake so it doesn’t get soggy.
Fridge: Store leftover vegan green bean casserole tightly covered in the fridge for 3 to 4 days.
Freezer: Wrapped tightly in plastic wrap and then foil, this casserole can be frozen for up to 6 months. Thaw in the fridge overnight and then bake as instructed until hot and bubbly.
Pro tips and tricks
~ Use frozen green beans for convenience and ease.
~ Be sure to thoroughly defrost the frozen beans and drain them well before adding to the casserole. If you skip this step, the beans may add too much moisture to the casserole causing it to become too watery.
~ If you use fresh green beans instead of frozen, blanch them for a few minutes, transfer to an ice bath, and drain well before adding them to the casserole.
~ Once you add the flour, make sure to bring the mixture to a boil before simmering until thickened.
~ If you prep the casserole a day in advance, wait to add the fried onion topping until you are ready to bake.
~ Bake until the topping is golden brown and crispy and the middle is hot and bubbly.
No, this vegan green bean casserole does not need to be covered when baking. The only exception would be if your fried onion topping is getting too dark before the casserole is hot and bubbly in the middle. In that case, loosely cover and continue baking until cooked through.
The casserole may be too watery for a couple of reasons: not enough thickener, frozen green beans weren’t defrosted and drained properly, or the casserole hasn’t cooked long enough. Make sure the green beans are fully defrosted and drained really well before adding them to the casserole. After the flour is added, the mixture must come to a boil and then be simmered long enough to thicken up.
Yes! This vegan green bean casserole can be made ahead of time, except for the fried onion topping. Do not add the topping until you are ready to bake. The casserole, without the topping, can be covered tightly with foil and kept in the fridge for a day until ready to bake. Remove the foil and sprinkle the topping on right before baking.
More vegan Thanksgiving recipes
- Roasted Rainbow Carrots
- Creamy Vegan Mashed Potatoes
- Spiced Orange Cranberry Sauce
- Maple Balsamic Brussels Sprouts
- Butternut Squash Mac and Cheese
- Dairy-Free Cornbread
- Vegan Mushroom Stuffing
I hope you love this recipe as much as we do! If you tried it, please use the rating system in the recipe card and leave a comment below with your feedback.
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Vegan Green Bean Casserole
- 3 tablespoons vegan butter
- 1 onion diced
- 1 teaspoon salt or to taste
- ½ teaspoon black pepper or to taste
- 8 ounces white button mushrooms diced
- 3 cloves garlic minced
- 3 tablespoons all-purpose flour
- 2 cups unsweetened, plain non-dairy milk
- 2 tablespoons nutritional yeast
- 1 tablespoon mellow white miso paste optional
- 24 ounces frozen cut green beans completely thawed and drained well (about 6 cups)
- 2 cups fried onions
- Preheat the oven to 350°F.
- Heat the butter in a large, deep skillet over medium heat. Add the diced onion and sauté until soft and translucent, about 4 to 5 minutes.
- Add the salt, pepper, mushrooms, and garlic. Sauté until the mushrooms have released their water, about 5 minutes.
- Sprinkle the flour over the top and stir well until no visible white flour remains.
- Slowly pour in the milk while whisking continuously to prevent clumping.
- Increase the heat to bring to a boil, then reduce the heat to medium-low and simmer 5 to 7 minutes, until thickened.
- Whisk in the nutritional yeast and miso paste, if using, until smooth.
- Add the green beans and stir well to coat.
- Transfer the mixture to the casserole dish. Sprinkle the fried onions evenly over the top.
- Bake for 15 to 20 minutes until the top is golden and the middle is hot and bubbly.
Nutrition values are calculated using online calculators and are estimates only. Please verify using your own data.
Genni DeMarco says
How much flour should be used? I don’t see the amount stated anywhere. Can it be substituted with cornstarch? This recipe looks delicious, and I am looking forward to trying it. Thanks! 🙂
Jenn Sebestyen says
Oh gosh, I’m so sorry. Thank you for catching that. It’s 3 tablespoons of flour. I’ve updated the recipe. Enjoy!
Genni DeMarco says
Thank you for responding so quickly! This is the first time I’ve had green bean casserole in probably DECADES (due to my plant-based dietary preferences), and this recipe definitely satisfied that nostalgic craving! Will definitely be bookmarking for future use, particularly for around the holidays!
Jenn Sebestyen says
Oh, I’m so glad to hear that! Thank you for your comment!