This Green Bean Casserole Gluten Free is the ultimate comfort classic made from scratch with fresh green beans and a creamy mushroom sauce. It’s naturally wholesome and ready in just over an hour, perfect for holiday dinners or a cozy family meal.

How to Make Green Bean Casserole Gluten Free

I rediscovered this dish while hosting our first gluten free Thanksgiving, aiming to reimagine the canned soup version with real, wholesome ingredients. The earthy aroma of sautéed cremini mushrooms mingling with garlic instantly filled my kitchen with a sense of homecoming. Now, it has become a non-negotiable centerpiece on our holiday table, nestled perfectly alongside my sweet potato casserole and a beautiful traditional Thanksgiving dinner spread. It’s a side dish that truly celebrates the season.

What Makes This Gluten Free Casserole Special

Made From Scratch Flavor: Fresh green beans and a homemade creamy sauce deliver far more flavor than any canned soup version.
Surprisingly Easy: With a straightforward process, this GF green bean recipe comes together with minimal fuss.
Crowd-Pleasing Comfort: It’s a family favorite that satisfies everyone, whether they follow a gluten-free diet or not.
Perfect for Holidays: This gluten free side dish can be prepped ahead, making your holiday meal planning smoother.

Ingredients for Your Perfect Green Bean Casserole

Be sure to see the recipe card below for the full listing of ingredients, instructions, notes, and estimated nutritional information.

Fresh Green Beans: Trimmed and blanched for the perfect tender-crisp texture.
Unsalted Butter: Provides a rich, savory base for sautéing the vegetables.
Cremini Mushrooms: Thinly sliced to release their deep, earthy flavor into the sauce.
Yellow Onion & Garlic: Finely chopped and minced for a sweet, aromatic foundation.
Gluten-Free All-Purpose Flour: A blend with xanthan gum is essential for thickening the sauce properly.
Chicken or Vegetable Broth: Low-sodium gives you better control over the final seasoning.
Whole Milk or Half-and-Half: Creates a luxuriously creamy sauce for this holiday GF recipe.
Gluten-Free Crispy Fried Onions: Divided to create a layered, crunchy topping that bakes up golden.

Green Bean Casserole Gluten Free

Make this delicious gluten-free green bean casserole with fresh green beans, cremini mushrooms, and crispy GF fried onions. Perfect holiday side dish ready in 75 minutes.

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Prep Time 25

Cook Time 46

Total Time 1 16

Course Side Dish

Cuisine American

Servings 6 servings

Calories 210 kcal

Equipment

oven
large pot
large skillet or Dutch oven
whisk
9×13-inch baking dish
knife
cutting board
measuring cups
measuring spoons
mixing bowl

Ingredients

Casserole Ingredients

1 pound fresh green beans, trimmed
4 tablespoons unsalted butter
8 ounces cremini mushrooms, wiped clean and thinly sliced
1/2 medium yellow onion, finely chopped
2 cloves garlic, minced
1/4 cup gluten-free all-purpose flour blend (ensure it contains xanthan gum)
2 cups low-sodium chicken broth or vegetable broth
1 cup whole milk or half-and-half
1 teaspoon fine sea salt, plus more to taste
1/4 teaspoon black pepper, freshly ground, plus more to taste
1 Pinch freshly grated nutmeg optional
6 ounces gluten-free crispy fried onions, divided

Instructions

Preheat your oven to 375 degrees Fahrenheit. If using fresh green beans, bring a large pot of salted water to a rolling boil. Add the trimmed green beans and cook for 3 to 5 minutes, or until they are vibrant green and slightly tender-crisp. Immediately drain the beans and plunge them into an ice bath to stop the cooking, then drain thoroughly again. If using frozen beans, thaw them completely and drain any excess liquid.
In a large, deep skillet or Dutch oven, melt the 4 tablespoons of unsalted butter over medium heat. Add the thinly sliced cremini mushrooms and sauté for 5 to 7 minutes, stirring occasionally, until they release their moisture and are deeply browned and tender. Stir in the finely chopped yellow onion and minced garlic, continuing to cook for another 3 to 4 minutes until the onion has softened and become translucent, and the garlic is fragrant.
Sprinkle the 1/4 cup of gluten-free all-purpose flour blend over the sautéed mushroom mixture. Stir continuously for 1 to 2 minutes, cooking the flour to create a light golden roux. This step helps to cook out the raw flour taste and will thicken your sauce beautifully.
Gradually whisk in the 2 cups of low-sodium chicken broth, followed by the 1 cup of whole milk. Continue whisking constantly as you bring the sauce to a gentle simmer. Let the sauce cook for 3 to 5 minutes, stirring occasionally, until it has visibly thickened to a creamy consistency that coats the back of a spoon. Season the sauce with 1 teaspoon of fine sea salt, 1/4 teaspoon of freshly ground black pepper, and an optional pinch of freshly grated nutmeg. Taste and adjust seasonings as needed.
Remove the skillet from the heat. Gently fold the blanched and drained green beans into the creamy mushroom sauce, ensuring all the beans are evenly coated.
Pour the green bean and sauce mixture into a 9×13-inch baking dish. Spread it evenly across the bottom of the dish. Sprinkle half of the gluten-free crispy fried onions evenly over the top of the casserole.
Transfer the baking dish to the preheated oven and bake for 25 to 30 minutes, or until the casserole is bubbling around the edges and the sauce is hot throughout.
Remove the casserole from the oven. Carefully sprinkle the remaining half of the gluten-free crispy fried onions over the top. Return to the oven for an additional 5 to 7 minutes, or until the onions are golden brown and crisp. Let the casserole rest for 5 minutes before serving warm.

Notes

Let the casserole rest for 5 minutes before serving for easier portioning.

Keyword gluten-free, green bean casserole, holiday

Simple Ways to Customize Your Casserole

Make It Cheesier: Stir in a half cup of shredded sharp cheddar cheese into the sauce before baking.
Add Protein: Fold in two cups of shredded cooked turkey or chicken for a heartier main dish.
Herb-Infused Version: Add a teaspoon of fresh thyme or rosemary to the mushroom sauté for an aromatic twist.

My Pro Tips for Perfect Results

Blanch for Texture: The ice bath is crucial for stopping the cooking process and keeping your green beans vibrant and crisp-tender.
Cook the Roux: Stir the gluten-free flour for a full minute to cook out the raw taste, which is key for a flavorful sauce.
Season in Stages: Taste the sauce after it thickens and again after combining with the beans to ensure perfect seasoning.
Layer the Topping: Adding half the onions before baking and the rest at the end ensures a crispy, non-burnt topping. For more make-ahead strategies, see my guide to easy Thanksgiving side dishes.

Cozy Serving of Green Bean Casserole Gluten Free

How to Store and Reheat Your Casserole

Store: Cool completely, then transfer to an airtight container and refrigerate for up to 4 days.
Freeze: Freeze the baked casserole (without the final onion topping) in a freezer-safe container for up to 3 months. Thaw in the refrigerator before reheating.
Reheat: Cover with foil and bake at 350°F for 15-20 minutes until hot, then add fresh crispy onions and bake uncovered for 5 more minutes.
Make-Ahead Tip: Assemble the casserole (without any topping) up to 2 days ahead; cover and refrigerate. Add the first layer of onions and bake as directed, adding 5-10 minutes to the initial baking time.

Frequently Asked Questions

Can I use frozen green beans for gluten free green bean casserole?

Yes, you can use frozen green beans for this gluten free casserole. Simply thaw them completely and drain any excess liquid well before adding them to the sauce. This saves prep time while still delivering great results.

What is the best gluten-free flour for green bean casserole?

I recommend a gluten-free all-purpose blend that contains xanthan gum, as it acts as a binder and helps create a smooth, lump-free sauce that thickens perfectly, just like a traditional roux.

How do you keep green bean casserole from getting soggy?

The key is to blanch the green beans briefly and cool them in an ice bath to stop the cooking. Also, make sure your sauce is properly thickened before combining, and don’t skip the step of adding the final crispy onions at the end.

Can I make green bean casserole gluten free ahead of time?

Absolutely. This is a fantastic make-ahead holiday GF recipe. You can assemble the casserole (without topping) up to two days in advance. Cover and refrigerate, then add the onions and bake when ready, adding a few extra minutes to the bake time.

More Gluten Free Side Dishes to Try

Why This Green Bean Casserole Gluten Free Will Become a Favorite

With its creamy, savory sauce and satisfying crunchy topping, this from-scratch version transforms a classic into something truly special. It’s incredibly easy to prepare and always receives compliments, making it a reliable star for any gathering. I hope it brings as much warmth and joy to your table as it has to mine.

Easy GF Casserole Recipe