Go Back Email Link
Close up of gluten-free green bean casserole in a baking dish ready for Thanksgiving.

Gluten-free Green Bean Casserole

Sara Vaughn
This gluten-free green bean casserole is the only gluten-free side dish you need on your holiday menu this year.
Prep Time 30 mins
Cook Time 45 mins
Total Time 1 hr 15 mins
Course Side Dish, vegetables
Cuisine American
Servings 8
Calories 287 kcal


Gluten-free Cream of Mushroom Soup

  • 1 ½ Cups Diced Mushrooms
  • 1 Small Shallot Small diced.
  • 3 Tablespoons Butter
  • 3 Tablespoons Cornstarch You can also use rice flour or arrowroot starch.
  • 1 Cup Chicken Stock You can also use vegetable stock for vegetarian.
  • ½ Cup Milk Or use a dairy-free alternative.
  • ¾ Teaspoon Salt
  • ½ Teaspoon Pepper
  • ¼ Teaspoon Thyme

For the gluten-free french fried onions.

  • 2 Medium White or Yellow Onions
  • 1 ½ Cups Buttermilk See my full gluten-free french fried onion post for a dairy-free alternative.
  • 1 ¼ Cups !;! Gluten-free Flour This works best with a rice based blend.
  • 1 ½ Teaspoons Salt
  • ½ Teaspoon Pepper
  • Oil for frying. See full post for alternative cooking methods.

For the gluten-free green bean casserole.

  • 4 Cups Green Beans Fresh are best.
  • 1 ½ Cups Sliced Mushrooms
  • 2-3 Cloves Minced Garlic 2 Teaspoons dried garlic.
  • 2 Tablespoons Butter You can also use olive oil.
  • ½ Teaspoon Salt
  • ½ Teasopoon Pepper
  • ¼ Teaspoon Thyme


Make the gluten-free cream of mushroom soup.

  • Add half of the butter to a skillet over medium-high heat and let it melt.
    3 Tablespoons Butter
  • Once the butter is melted, add the diced mushrooms and shallot. Let them saute until they become soft and they get some color.
    1 ½ Cups Diced Mushrooms, 1 Small Shallot
  • Once the vegetables have cooked some, add the remaining butter and the corn starch. Stir the vegetables and starch until no dry starch is visible.
    3 Tablespoons Butter, 3 Tablespoons Cornstarch
  • Whisk in the chicken stock and milk.
    1 Cup Chicken Stock, ½ Cup Milk
  • Add the spices and let it simmer until it thickens and starts to look like a thick gravy that will coat the back of a spoon.
    ¾ Teaspoon Salt, ½ Teaspoon Pepper, ¼ Teaspoon Thyme
  • Set the cream soup aside while you make the rest of the casserole.

Make the french fried onions for topping.

  • Slice the onions.
    2 Medium White or Yellow Onions
  • Soak the onions in the buttermilk for at least 15 minutes.
    1 ½ Cups Buttermilk
  • Slightly dry the onions on some paper towels.
  • Combine the gluten-free flour and spices into a bowl.
    ½ Teaspoon Pepper, 1 ¼ Cups !;! Gluten-free Flour, 1 ½ Teaspoons Salt, ½ Teaspoon Pepper
  • Dredge the soaked onions into the flour to coat.
  • Warm your oil until it reaches about 350 °F
    Oil for frying.
  • Quick fry the coated onions until they are golden.
  • Remove the onions from the oil and let them cool on some paper towels to remove any excess oil.

Make the gluten-free green bean casserole.

  • In a skillet over medium-high heat, add half the butter and mushrooms
    2 Tablespoons Butter, 1 ½ Cups Sliced Mushrooms
  • Once the mushrooms have softened and gotten some color, add the remaining butter and green beans.
    2 Tablespoons Butter, 4 Cups Green Beans
  • Let the mushrooms and green beans saute until the green beans start to soften, about 5-7 minutes. You want them to release some of their liquid, so you don't end up with a watery casserole.
  • Add the minced garlic, and let them cook for another minute, just until the garlic becomes fragrant.
    2-3 Cloves Minced Garlic
  • Add the spices. - Taste your vegetables to make sure they are seasoned to your liking.
    ½ Teaspoon Salt, ½ Teasopoon Pepper, ¼ Teaspoon Thyme
  • Stir in your reserved cream of mushroom soup into your green beans and mushrooms.
  • Transfer the mixture to a lightly greased baking dish.

Top and bake.

  • Top the casserole with your gluten-free french fried onions.
  • Preheat your oven to 375 °F.
  • Place your green bean casserole into the oven uncovered.
  • Bake the casserole in the oven for about 45 minutes or until the center of the casserole is bubbly.
  • Let it rest for about 10 minutes before serving.


See the full recipe posts for my gluten-free cream of mushroom soup and gluten-free french fried onions to see all the tips and tricks.
Tips and tricks for making the best green bean casserole.
  • Your green beans matter. - I know traditional green bean casserole is made with canned beans, but using canned beans can make this side dish very mushy because the beans are already very soft. I prefer to use fresh green beans if possible. My second choice is frozen green beans. If you use frozen green beans, be sure to let them defrost before using them.
  • Season each layer. - Because there are so many different layers coming together to make this casserole, it's important to make sure each layer is seasoned well and to your liking. I always taste and adjust as I put it together.
  • Make this a dairy-free green bean casserole by making a dairy-free cream of mushroom soup and some dairy-free french fried onions.
Keyword gluten free grean bean casserole, gluten free green beans, gluten free side dish, gluten free thanksgiving, gluten free thanksgiving side dish