How Long To Cook Green Bean Casserole At 425

My Healthy Green Bean Casserole is a fresh take on the classic using tender green beans, a creamy homemade mushroom alfredo sauce, and, of course, a crispy onion topping made from scratch! This gluten free green bean casserole is a new family favorite holiday side dish. This post contains affiliate links for products I'm obsessed with.

Overhead image: green bean casserole with crispy onion topping in a white casserole dish with a wooden spoon.

Healthy Green Bean Casserole

Every year when I ask on social what holiday recipe you want me to recreate, green bean casserole is always requested.

I'll admit, I dragged my feet a bit. I tested it a couple of times last year, and then I let it go. The truth? I haven't really been a big fan of Green Bean Casserole and I tend to skip it to make room for more Sweet Potato Casserole. However, because I love you all, and I am SO thankful for you, I decided to give it another shot this year. After three more rounds of testing, I'm here with a Green Bean Casserole that's a fresh and healthy alternative to the classic recipe.

And you know what? I am kind of obsessed now.

Ingredients for Gluten Free Green Bean Casserole

What exactly makes this green bean casserole healthier? The super fresh ingredients! We are ditching the canned, condensed soups for a creamy, dreamy mushroom Alfredo sauce based off of my popular recipe.

Also, instead o frozen or canned green beans which tend to get soggy, we are using fresh! And I even have options for a homemade crispy onion topping (or some recommendations for cleaner, GF store bought fried onions!).

Here's more info on what you will need:

Fresh green beans: You'll need about 1 1/2 pounds, trimmed and cut into bite-sized pieces.

Overhead image: fresh cut green beans in a white casserole dish

For the Mushroom Alfredo Sauce:

Not gonna lie, this mushroom alfredo has my heart!

butter: Feel free to use vegan butter or olive oil instead.
baby bella mushrooms: It's super important to get cremini or baby bella mushrooms for this recipe, as white mushrooms won't give your Alfredo enough flavor. I get them already sliced and then just dice them up a bit more before sautéing.
garlic: 4-5 nice size cloves, or more if you love it!
gluten free flour: I use Bob's Red Mill 1:1 flour. You can definitely swap whole wheat flour if you aren't gluten free.
original unsweetened almond milk: You can swap this for the milk of your choice, but I love that almond milk contains less calories than dairy free milk, and is just as creamy.
sharp white cheddar cheese: I love the extra creaminess and flavor that sharp cheddar adds to alfredo sauce! Be sure to use freshly grated cheese for best results.
Parmesan Reggiano cheese: Again, freshly grated and packed in tight for optimal cheesiness!
salt, fresh ground pepper, and a dash of nutmeg: The nutmeg is optional, but I highly recommend it!

High angle view: fresh green beans topped with homemade mushroom alfredo sauce in a casserole dish.

For the Crispy Onion Topping:

yellow or red onions: Sliced super thin, you want about 1 ½-2 cups of onions
olive oil cooking spray: Can sub avocado oil spray
gluten free panko breadcrumbs: You can sub whole wheat panko if not GF.
garlic powder: For some great flavor.
salt: Brings everything together.
Parmesan cheese: Freshly grated is the way to go!

Can't part with the Canned Onion Topping? I love Aldi's Organic Gluten Free Fried Onions! You can sub one cup of those in this recipe instead of making your own, if you prefer!

Overhead photo: green bean casserole with crispy onions and mushroom alfredo, golden brown and ready for serving.

How to make this Gluten Free Green Bean Casserole

While a little time consuming, this casserole is very easy to put together! The full recipe is in the card below, but you are basically going four simple steps.

Step one: Boil your green beans

Step two: Make your crispy onion topping

Step three: Prep your mushroom alfredo

Step four: Assemble casserole and bake

That's all there is to it!

How to make green bean casserole ahead of time

You can also easily make this healthy green bean casserole ahead to save time during Thanksgiving. Here's what I recommend:

Prepare the recipe as directed, and add the crispy onions on top, but do not bake. Wrap with foil and place in fridge up to 2 days ahead.
Once ready, bake as directed. I like to take it out of the fridge at least 30 minutes prior, so it's not super cold going into the oven.
Serve immediately with all your favorite Thanksgiving dishes.

How Long Will This Healthy Green Bean Casserole Stay Fresh?

You can store any leftover Green Bean Casserole covered in foil or in an airtight container in the fridge for up to four days. When reheating, simply pop in the microwave or back in the oven until warmed through.

Green bean casserole in a white casserole dish with black and pink text on a white rectangle. Text says "Gluten Free Green Bean Casserole | No Canned Anything!"

More Healthy, Gluten Free Thanksgiving Sides

Healthy Sweet Potato Casserole

Crispy Brussels Sprouts with Bacon, Parmesan, and Balsamic

Instant Pot Mashed Potatoes

Cauliflower Au Gratin

Instant Pot Cranberry Sauce

Butternut Squash Mac and Cheese

Description

My Healthy Green Bean Casserole is a fresh take on the classic using tender green beans, a creamy homemade mushroom alfredo sauce, and of course a crispy onion topping made from scratch! This gluten free green bean casserole is a new family favorite holiday side dish.

Green Beans

1 1/2 pounds fresh green beans, trimmed and cut into bite-sized pieces

For the Crispy Onion Topping

1 large or 2 small yellow or red onions, sliced super thin – you want about 1 ½–2 cups of onions for this

olive oil cooking spray

1/2 cup gluten free panko breadcrumbs (can sub whole wheat)

1/2 teaspoon garlic powder

1/2 teaspoon salt

¼ cup parmesan cheese

**Can't part with the Canned Onion Topping? I love Aldi's Gluten Free Fried Onions! You can sub one cup of those in this recipe!

Mushroom Alfredo Sauce

4 tsp butter, vegan butter, or olive oil, divided

8 ounces baby bella mushrooms, thinly sliced

4–5 cloves of garlic, minced

2 tablespoons gluten free or whole wheat flour

1 3/4 cup original unsweetened almond or cashew milk

1/4 cup freshly shredded sharp white cheddar cheese, packed in tight (can sub for parmesan)

1/3 cup freshly grated Parmesan Reggiano cheese, packed in tight

fresh ground pepper

1/4 tsp salt + more to taste

a dash of nutmeg

Preheat oven to 425 degrees F. Line a large baking sheet with parchment paper and spray with olive oil spray. Then grease a 9×13-inch baking dish with olive oil spray. Set both aside.
Fill a large saucepan with water and bring to a boil over high heat. Add in your green beans and cook for 5 minutes. Drain beans and place in prepared baking dish.
Meanwhile, while you are waiting for the water to boil and the beans to cook, make your Crispy Onion Topping.
Place sliced onions in a large bowl and spray liberally with olive oil spray. Add in panko bread crumbs, garlic powder, salt and parmesan cheese. Use your hands to toss to combine, then place onions onto prepared baking sheet. Spray everything with olive oil spray again and bake for 10-15 or until the breadcrumbs are golden and the onions are crispy.
Next, prepare your mushroom alfredo sauce. Heat a ceramic or stainless steel pan over medium heat. Add in 2 teaspoons of butter , then add the mushrooms and sauté for 5 minutes, stirring occasionally, until lightly browned and soft. Add garlic and the remaining butter, and sauté for 1-2 more minutes, stirring occasionally, until fragrant. Slowly whisk in flour until well combined. Slowly whisk in almond milk. Increase heat to medium high and allow milk and flour to thicken for several minutes. Once your roux is thickened, reduce heat to low and add in all the cheese, stirring well until the sauce is creamy. Remove from heat. Add in ¼ tsp of salt (or to taste), a sprinkle of pepper, and a pinch of nutmeg. Mix in 1/4 cup of the crispy onion topping.
Pour mushroom alfredo sauce over green beans, then top with the remaining crispy onion topping.
Bake for 25-30 minutes or until everything is warmed and topping is golden brown. (Keep an eye on it so that it does not burn. If it does start to get too dark, simply lay a piece of aluminum foil on top of the casserole.)

Notes

Makes 8-10 servings

21 Day Fix: 1+ GREEN, 1/2 YELLOW, 1/4 BLUE, 1/2 TSP (per serving)

**If you top with the Aldi Crispy Onions, count an extra TSP per serving.

Keywords: healthy green bean casserole, gluten free grean bean casserole