Gluten-Free Green Bean Casserole

By
Diana Rattray
Diana Rattray
Diana Rattray
Southern-cuisine expert and cookbook author Diana Rattray has created more than 5,000 recipes and articles in her 20 years as a food writer.
Learn about The Spruce Eats' Editorial Process
Updated on 11/15/22
Tested by
Colleen Graham
Photo of Colleen Graham
Tested by Colleen Graham
Freelance writer and cocktail book author Colleen Graham is a seasoned mixologist who loves sharing her knowledge of spirits and passion for preparing drinks.
Learn about The Spruce Eats' Editorial Process
Gluten-Free Green Bean Casserole

The Spruce / Abbey Littlejohn

Prep: 20 mins
Cook: 70 mins
Soak Time: 5 mins
Total: 95 mins
Servings: 6 servings
Yield: 1 casserole
Nutrition Facts (per serving)
532 Calories
34g Fat
44g Carbs
14g Protein
Show Full Nutrition Label Hide Full Nutrition Label
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Nutrition Facts
Servings: 6
Amount per serving
Calories 532
% Daily Value*
Total Fat 34g 44%
Saturated Fat 7g 34%
Cholesterol 25mg 8%
Sodium 1201mg 52%
Total Carbohydrate 44g 16%
Dietary Fiber 5g 18%
Total Sugars 11g
Protein 14g
Vitamin C 14mg 68%
Calcium 398mg 31%
Iron 3mg 15%
Potassium 459mg 10%
*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.
(Nutrition information is calculated using an ingredient database and should be considered an estimate.)

A creamy green bean casserole is an essential side dish for any holiday meal, especially Thanksgiving, and it can easily be made gluten-free. Most standard cream of mushroom soups and crispy fried onions contain gluten, but there are alternatives. This version is made with gluten-free cream of mushroom soup and homemade crispy fried onions coated with buttermilk and a gluten-free flour blend. If you're short on time or not a fan of onions, feel free to top the casserole with crumbled gluten-free potato chips, breadcrumbs, or croutons.

Many gluten-free cream soups are on the market, from condensed versions to soups that don't require additional milk. Be sure to check the labels—it should specifically state "gluten-free." If your soup doesn't require milk or water, you may want to stir in some heavy cream or sour cream for richer flavor and creaminess. If you have time, make gluten-free cream of mushroom soup from scratch. The homemade version allows you to flavor it as you like, and it'll be preservative-free.

Serve the gluten-free green bean casserole with your Thanksgiving feast, or take it along to a holiday potluck. You don't have to wait for a holiday—it's fabulous with a Sunday roast chicken or everyday weeknight family meal.

"While there are multiple things to cook and prep for this recipe, the result is worth the effort. The onions are fantastic, and you’ll likely have plenty to snack on as you cook. Overall, it has a classic green bean casserole taste that you’d never expect to be gluten-free." —Colleen Graham

Gluten-Free Green Bean Casserole /Tester Image
A Note From Our Recipe Tester

Ingredients

For the Gluten-Free Crispy Fried Onions

  • 2 medium onions, thinly sliced

  • 1 1/2 cups buttermilk

  • Vegetable oil, for frying

  • 1 1/2 cups gluten-free flour blend

  • 1 1/2 teaspoons baking powder

  • 1 1/2 teaspoons kosher salt, more as needed

  • 1/4 teaspoon freshly ground black pepper

For the Gluten-Free Green Bean Filling

Steps to Make It

Prepare the Gluten-Free Fried Onions

  1. Gather the ingredients for the fried onions.

    fried onion ingredients

    The Spruce / Abbey Littlejohn

  2. Put the sliced onions in a large bowl and add the buttermilk. Stir to coat and let stand for 10 minutes.

    sliced onions in a bowl with buttermilk

    The Spruce / Abbey Littlejohn

  3. Meanwhile, add about 2 inches of oil to a large Dutch oven, or other heavy-duty pot. Heat the oil to 370 F. Line a large platter or baking sheet with paper towels. Set aside.

    oil in a pan, paper towel lined baking sheet

    The Spruce / Abbey Littlejohn

  4. In a separate large bowl, combine the gluten-free flour blend, baking powder, 1 1/2 teaspoons of salt, and 1/4 teaspoon of black pepper. Mix thoroughly.

    gluten-free flour blend, baking powder, salt, and black pepper in a bowl

    The Spruce / Abbey Littlejohn

  5. Shake off the excess buttermilk and toss about half of the soaked onions in the gluten-free flour mixture until well coated.

    onions in a flour mixture

    The Spruce / Abbey Littlejohn

  6. Fry the onions, turning half way through cooking time until golden, 2 to 2 1/2 minutes total.

    onions frying in a saucepan

    The Spruce / Abbey Littlejohn

  7. Transfer the fried onions to the paper towels. Sprinkle lightly with salt. Repeat with the remaining onions and set aside. 

    fried onions on a baking sheet

    The Spruce / Abbey Littlejohn

Prepare the Gluten-Free Green Bean Filling

  1. Gather the ingredients for the green bean casserole.

    Position a rack in the center of the oven and heat to 350 F.

    Gluten-Free Green Bean Filling ingredients

    The Spruce / Abbey Littlejohn

  2. If using fresh green beans, bring a large pot of well salted water to a boil. Add the green beans and cook until tender, about 5 to 6 minutes. Drain well. If using frozen green beans, follow thawing instructions on the package and drain well. If using canned green beans, drain well—no cooking required.

    green beans in a colander

    The Spruce / Abbey Littlejohn

  3. In a large bowl, combine the cooked green beans with the soup, milk, Worcestershire sauce or soy sauce, and half of the cheese. Crumble about 1 cup of the fried onions and fold them into the green bean mixture. Adjust the seasoning with salt, pepper, and garlic powder as desired.

    Combine the cooked green beans with the soup, milk, Worcestershire sauce or soy sauce, and cheese in a bowl

    The Spruce / Abbey Littlejohn

  4. Turn the green bean mixture into an ungreased 2-quart baking dish. Bake until the mixture is warmed through, about 25 minutes.

    green bean filling in a baking dish

    The Spruce / Abbey Littlejohn

  5. Top the casserole with the remaining cheese and an even layer of the remaining fried onions. Bake until the cheese is melted and the filling is bubbly, 5 to 8 minutes more. Serve.

    Gluten-Free Green Bean Casserole

    The Spruce / Abbey Littlejohn

Tips

  • When deep-frying the onions, avoid overcrowding the pan. Split the onions into smaller batches if needed. Let the oil temperature come back to 370 F between batches or the onions won't be crispy and will absorb too much oil.
  • If you have extra fried onions, they make a tasty snack or topping for sandwiches and burgers.
  • To transport a hot cooked green bean casserole, use newspapers or a blanket to insulate it and keep it hot. Never leave a hot dish out at room temperature for more than two hours.

Recipe Variations

  • For a bacon-cheddar green bean casserole, add four strips of cooked, crumbled bacon to the casserole with the cheese.
  • Omit the fried onions and top the casserole with one cup of fresh breadcrumbs tossed with two tablespoons of melted butter and a dash of salt and pepper.
  • Instead of fried onions, top the casserole with about 1 1/2 cups of crumbled gluten-free potato chips.


How to Store

  • Refrigerate leftover green bean casserole in a shallow covered container within two hours and eat within four days.
  • To freeze leftover green bean casserole, transfer it to an airtight freezer container and freeze for up to six months. Defrost it in the refrigerator overnight and reheat, covered, in the microwave or a 350 F oven. The minimum safe internal temperature for cooked leftovers is 165 F.
  • The crispy fried onions may be made ahead of time and stored in an airtight container or zip-top bag in the fridge for up to one week.
  • To re-crisp leftover fried onions, spread them out on a baking sheet and bake them in a preheated 350 F oven for 4 to 5 minutes, or until hot and crispy.


Why is my green bean casserole runny?

To prevent a runny green bean casserole, make sure your cooked green beans are completely drained before mixing them with the soup. A soup or sauce that's too thin can also cause a runny casserole. To thicken the soup, mix one tablespoon of cornstarch with an equal amount of cold water. Heat the soup in a saucepan over medium heat and add about half of the slurry mixture. Continue to cook until the soup is thickened, adding more of the slurry as needed.