Vegan Green Bean Casserole

This Vegan Green Bean Casserole recipe features tender green beans and mushrooms in a creamy sauce, topped with crispy onions. A homemade Healthy Green Bean Casserole is easy to make and has the ultimate creamy mushroom filling!

Looking down on a casserole dish full of green bean casserole.
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I grew up in a small, rural town in the middle of Missouri. The only green bean I was familiar with was the ones that came out of a can. It’s not that we didn’t have fresh green beans. We actually even grew some in our back yard garden. I just wouldn’t eat anything that wasn’t from a can.

And then when I was introduced to the green bean casserole, I was not impressed. What can I say, I was a finicky eater!

Green Bean Casserole From Scratch!

Somewhere along the way I found out how much I loved fresh green beans steamed with some olive oil and garlic. And then I decided, why not make a green bean casserole with fresh green beans?

My world was changed! Of course, I had to make that green bean casserole vegan too. In fact, I decided to make the entire green bean casserole from scratch, including the fried onions. I’m so pleased with the results:

  • No slimy canned mushroom soup (it’s not vegan!)
  • Fresh green beans bursting with flavor, texture, and nutrition
  • Vegan cheesy homemade sauce
  • Homemade “fried” onions.

There’s nothing like tender green beans served with the ultimate creamy, cheesy mushroom filling and topped with crispy fried onions!

Of course, making it homemade can take a little more time. However, I have a trick to make this recipe go a lot faster, while still giving you the taste and texture of fresh green beans. I’m excited to share it with you!

Looking down on the edge of a casserole dish holding green bean casserole.

How to Make Vegan Green Bean Casserole Recipes

There are a few steps to making this delicious vegan green bean casserole, but I’ll share with you some time-saving tips too!

  1. Fried Onions. Marinate the onions in vegan buttermilk, then coat in a flour mixture and fry in a skillet using vegetable oil. Be sure to save any leftover flour and milk from this step!
  2. Make the Cheesy Sauce. Melt butter in a skillet and add the mushrooms and cook until they’re nice and tender. Next, add some garlic, and cook until tender. We’ll combine the leftover buttermilk and flour from the fried onions and add that to the skillet. Watch and stir as it transforms into a delicious sauce!
  3. Add Green Beans. I’m calling for frozen green beans here. They have the flavor of fresh, but you get to skip all that chopping. Besides they don’t need as much time to cook. So, add the frozen green beans to the skillet, stirring to coat them. Bring that to a simmer and add the vegan cheese. Cook until that melts and then stir in some of the fried onions (reserving plenty for the topping).
  4. Bake. Transfer the contents from the skillet to a casserole dish and top with the rest of the fried onions and some vegan parmesan. Then bake at 375°F for 20 minutes, until the sides are bubbly and the onions are golden brown.
A skillet is full of green beans and mushrooms cooking.

How to Make Fried Onions

I recommend marinating onions in a mixture of plant-based milk and apple cider vinegar (basically, vegan buttermilk) for 20 – 30 minutes prior to frying them. You can even soak them overnight.

This marinade helps soften the onion flavor and the buttermilk mixture will help the flour coating stick to the onions.

A bowl holds sliced onions are marinating in vegan buttermilk.

Gluten Free Fried Onions

You can use gluten-free flour to make gluten free fried onions, however, I find that the flour doesn’t brown as much. To help gluten free fried onions turn a more golden color, I recommend coating the top of the fried onions (immediately before baking) with a mixture of 1 tablespoon melted vegan butter combined with 1 teaspoon agave nectar.

To make a gluten free dairy free green bean casserole, simply substitute an all purpose gluten-free flour in the sauce as well. I used Bob’s Red Mill 1:1 gluten free flour and it worked great in this recipe.

Healthy Green Bean Casserole Recipe

You may already know this, but green beans are healthy. The green color gives it away. So, it’s the things added to green beans that causes a dish like green bean casserole to tip on the scale towards unhealthy. The main culprit? Fried onions.

So, to make this green bean casserole healthy, I recommend using an air fryer to make the fried onions. It’s easy to do!

Set the temperature of your air fryer at 375°F and fry for 10 – 15 minutes. Marinate the onions and coat them in flour and then add them to the air fryer basket. When air frying, be sure to remove the basket and toss the onions every 5 minutes or so.

A casserole shows fried onions in a casserole dish with green beans.

Can you make green bean casserole ahead of time?

It’s easy to make green bean casserole ahead of time by preparing the casserole as directed. Then cover and refrigerate the casserole for up to 3 days. When you’re ready to serve, bake it for 20 minutes in the oven at 375°F.

Can you freeze green bean casserole?

Green bean casserole can be frozen for up to 3 months. Transfer the casserole to a freezer safe container and place in the freezer. The day before you’re ready to serve it, transfer it to the fridge to thaw overnight. Then bake it at 375°F for 20 – 30 minutes.

I love these tips to make vegetarian green bean casserole ahead of time! It keeps the day of your big feast more stress-free, which is perfect!

Looking down on a spoon in a casserole dish full of green bean casserole.

More Vegan Thanksgiving Recipes

Sure, you love this easy vegan green bean casserole! If you’re looking for even more tasty vegan Thanksgiving recipes, you’ll love these:

For more vegan green bean recipes, be sure to check out these Balsamic Green Beans. It’s a perfect side dish for any recipe!

A hand holds a fork full of vegan green bean casserole with the rest of the dish behind it.

I hope you love this recipe as we do! Have you tried it? Be sure and leave a comment and a rating of this recipe below and then take a quick photo and share it with me using #namelymarly on Instagram. I love seeing your creations!

Looking down on a casserole dish full of green bean casserole.

Vegan Green Bean Casserole

This amazing Vegan Green Bean Casserole is a gluten-free recipe made with fresh green beans that are simmered in a savory mushroom sauce. Of course, the casserole is topped with crispy pan-fried onions too.
Print Pin Rate
Course: Side Dish
Cuisine: American
Keyword: Vegan Green Bean Casserole
Prep Time: 10 minutes
Cook Time: 45 minutes
Resting Time: 10 minutes
Total Time: 1 hour 5 minutes
Servings: 6 servings
Calories: 277kcal
Author: Marly

Ingredients

For the French fried onions:

  • 1 cup plant-based milk (plain, not vanilla)
  • 1 teaspoon apple cider vinegar
  • 1 medium onion , peeled and sliced into thin rings
  • 3/4 cup all-purpose flour
  • 1/2 teaspoon salt
  • 1/4 teaspoon black pepper
  • 4 tablespoons vegetable oil

For the Casserole:

  • 4 tablespoons vegan butter , divided
  • 2 cups portobello mushrooms , washed and sliced
  • 4 cloves garlic , peeled and minced
  • 1 cup water , plain, not vanilla
  • 2 teaspoons Better than Bouillon No Chicken Base**
  • 1/2 cup vegan cheddar shreds
  • 1/4 teaspoon black pepper
  • 10 ounce bag frozen green beans
  • 1/4 cup vegan parmesan cheese

Instructions

To Make the Fried Onion Topping:

  • In a medium-sized bowl stir together the milk and vinegar. Add onion rings and use a spoon to stir and coat them. Set aside for onions to marinade for approximately 30 minutes.
  • On a large plate, stir together flour, salt, and pepper.
  • Use tongs to pull a small batch of the onions from the milk mixture, danging them over the bowl to let excess liquid drip off. Transfer the onions to the flour mix. Repeat until all onions have been transferred. Use tongs to toss and coat. Reserve the milk mixture for the casserole.
  • Cover a plate with 2 – 3 paper towels. Heat 1 tablespoon oil in a large skillet over medium heat. Once the oil is heated, add some of the battered onions in an even layer across the pan with minimal overlapping. Cook 2 – 3 minutes and use tongs to gently toss. Cook for 2 – 3 minutes again and then toss again. The onions should begin to turn a golden brown and become crispy on the edges. Transfer cooked onions to paper towel lined plate. Repeat this step with remaining onions.

For the Green Bean Casserole

  • In a skillet over medium heat, add vegan butter. Heat up the oil then add the mushrooms and cook until tender, about 3 minutes. Add minced garlic. Stir and cook for about 30 seconds.
  • Combine the milk mixture from the onions above, with 1 cup water, and bouillon. Stir to combine. Use any leftover flour from the fried onions and add 3 tablespoons flour to the milk mixture. Stir to remove any lumps. Pour this over the contents in the skillet and stir to combine.
  • Add the green beans, stir to coat and then bring it to a simmer. Add vegan cheese and stir until it melts. Then reduce heat to medium-low and cook for approximaely 5 minutes, until the green beans are no longer frozen and slightly tender, but still a little crisp and the sauce has thickened. If the sauce does not thicken, sprinkle another tablespoon of flour over the top and use a spatula to stir it in.
  • While the green beans simmer, preheat oven to 375°F.
  • Pour the green bean mixture into a 9" square baking dish or casserole dish. Add about 1/2 of the fried onions and stir them throughout. Equally distribute remaining fried onions over the top. Srinkle with vegan parmesan. Bake for 20 – 25 minutes.
  • When done, remove from oven and set aside to cool for 5 – 10 minutes before serving. Cover and refrigerate any leftovers not eaten right away. These will keep in the fridge for up to 5 days.

Notes

  1. Make-ahead Tips: Prepare the green bean casserole ahead of time, including baking. Allow it to cool to room temperature and then cover and refrigerate. To serve, remove from the fridge and let it sit until it is room temperature then reheat in the oven at 375°F for 15 minutes
  2. Fried Onions. Most store-bought Fried Onions are vegan as well, so you can substitute store-bought onions if you prefer to skip frying them yourself.
  3. Mushrooms: You can leave out the mushrooms if you prefer.
  4. Vegan Cheese: I used Daiya cheddar shreds, but Follow Your Heart cheddar shreds could work here too.
  5. Double the recipe: It’s easy to double this recipe. Simply use double the ingredients and transfer to a larger casserole dish, such as a 9X13. Top with fried onions, then bake, around 25 minutes, until bubbly around the edges.

Vegan green beans recipes are the best — Enjoy!

Updated by Marly · Permalink