This Keto Green Bean Casserole Recipe is everyone's favorite side dish at the Thanksgiving table. This classic holiday side dish is made with fresh green beans, a homemade cream of mushroom soup base, and the classic crunchy onion toppings.
This recipe is just as tasty as traditional green bean casserole, but made (mostly!) from scratch and more suitable for a low carb or keto diet with a lower carb count. Delight your guests by making a decadent, homemade green bean side that's loved by the whole family.
Looking for more keto recipes to serve this holiday season? Don't forget to make a batch of keto cranberry sauce, these keto maple glazed carrots, or these mashed turnips for side dishes!
Note: This recipe was originally published in November 2016, but has been improved and re-photographed. We hope you enjoy the new look!
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❤️Why we love this recipe
- Simple ingredients - You can find what you need for this recipe at any grocery store during the holiday season!
- Make ahead - This recipe is great to make ahead of time to save time on the big day. After assembling in advance, you can either bake or just reheat the casserole in the oven.
- Even better than the traditional version - This is a favorite holiday side dish for many, and honestly, it's even better than the regular version with the luscious mushroom soup base made from scratch!
🧄Ingredients
Here are the ingredients we used for this easy keto cranberry sauce. You can find more information for substitutions below.
- Fresh green beans
- Kosher salt & black pepper
- Unsalted butter
- Heavy whipping cream
- Chicken broth
- Fresh mushrooms
- Onion
- Garlic
- Xanthan gum
- Crispy onions - Yes, the store-bought kind. They aren't the "cleanest" keto ingredient, but they can work when spread out over many servings. Keep reading for ideas for substitutions if you don't want to use French fried onions.
Visit the recipe card for the full quantities and nutritional information.
✨Substitutions & variations
Here's a few suggestions on additional flavors to try, or simple variations to this sauce.
- More protein - Add chicken bone broth instead of chicken stock or broth to add more nutrients, flavor, and protein!
- Cheesy - Love cheese? Be sure to add some cheddar cheese, parmesan cheese, or both to the beans before baking if you like!
- Tangy - Love a little extra zip? Try adding a tablespoon or two of dijon mustard to the cream of mushroom soup mixture.
- Umami - If you want to ramp up the savory umami flavor, you can add a tablespoon of Worcestershire sauce or soy sauce to the mushroom soup mix.
- Time saver - While we highly recommend using fresh onion and garlic for the best flavor, if you're in a pinch, you can always use onion powder and garlic powder instead.
- No xanthan gum - If you don't have xanthan gum available to you, try adding it some softened cream cheese to thicken the cream of mushroom soup mixture. Arrowroot powder is another option to try, though you will need to use more of it (up to 2 tablespoons) in place of around ½ a teaspoon of xanthan gum,
- Lower the carbs - If you want to bring the net carbs to about 5g per serving, swap out the crispy onions for pork rinds or pork rind crumbs (affiliate link).
🔪Prep work
- Mince onions, mushrooms, and garlic.
- Trim the green beans.
- Measure out all ingredients.
- Prep a large bowl of cold water and add lots of ice.
- Preheat the oven to 350°F.
📋Instructions
In a large stock pot or dutch oven, bring water to a rolling boil, and add lots of salt. Since the beans will only be in the water for a few minutes, you want the water to be really salty. Boil until beginning to soften, but still crispy and bright green, about 3-5 minutes. (Image 1) Transfer the beans to a large bowl of cold ice water to stop the cooking process. (Image 2)
Drain the beans from the cold water, and add to a large skillet or casserole dish. Season with about 1.5 teaspoons of salt, and set aside. (Image 3).
Heat a large skillet over medium heat on the stove. Melt butter, add onion with a pinch of salt, and cook until translucent, about 3-5 minutes. Then, add in garlic and cook until fragrant, about 30 seconds. (Image 4) Add in mushrooms with more salt and cook for about 5 minutes to soften. (Image 5)
Reduce heat to medium-low, and add chicken broth and heavy cream to the skillet. (Image 6)
Simmer the soup mixture, and add in xanthan gum, stirring often. (Image 7) Allow the sauce to thicken and simmer for 5-10 minutes, adjusting seasoning to taste. (Image 8)
Add the mushroom soup mixture, and toss with green beans to combine. (Image 9) Add the crispy topping to the top of the casserole, then bake, covered with aluminum foil for 25 minutes. (Image 10)
Remove foil, and bake for another 10-15 minutes, until the crispy onions are golden brown. Enjoy!
✨Tips & tricks
- Add in xanthan gum slowly and stir frequently, a little bit goes a long way, and keep in mind that the sauce will thicken as it cools.
- Don't be shy about adding salt to the water for boiling the beans. You will need at least 3 tablespoons of kosher salt.
- Don't overcook the green beans. The idea is for the green beans to still have a lot of "snap" to them before they go into the oven, where they will continue to soften.
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💭Frequently Asked Questions
Allow to cool at room temperature, then store in an airtight container in the fridge for up to 5 days. To reheat, cover them with foil and reheat at 350°F for about 15-20 minutes so that the topping stays crispy. You can also reheat in the air fryer or microwave.
We don't recommend freezing this recipe.
Yes, this recipe can be made in advance. Simply follow the instructions to blanch the green beans and make the mushroom soup, then cover with foil and store in the fridge for up to 3 days. Before baking, top with the crispy onions and bake as usual.
More Recipes To Consider
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📖 Recipe
Keto Green Bean Casserole
Equipment
- stock pot
- large bowl
- casserole dish (9x13 inch or larger)
Ingredients
Casserole
- 2 pounds fresh green beans, trimmed
- 2 teaspoons kosher salt (to taste)
- bowl of ice water
- 6 ounces French fried onions (store-bought)
Cream of mushroom soup base
- 4 tablespoons unsalted butter
- 1 medium yellow onion, minced
- 3 cloves garlic, minced
- 8 ounces baby bella mushrooms, minced
- ½ teaspoon xanthan gum (added slowly to thicken)
- 8 ounces chicken broth (1 cup)
- 8 ounces heavy whipping cream (1 cup)
Instructions
- Preheat the oven to 350°F. Bring a large stock pot full of water to a rolling boil. Add 3-4 tablespoons of kosher salt to the pot, followed by the green beans. Cook for 3-5 minutes, until the beans have softened but are still bright green, then, immediately remove them from the boiling water and transfer them to a large bowl of ice water. Drain the beans from the cold water, and add to a large skillet or casserole dish. Season with about 1.5 teaspoons of salt, and set aside
- Heat a large skillet over medium heat on the stove. Melt butter, add onion with a pinch of salt, and cook until translucent, about 3-5 minutes. Then, add in garlic and cook until fragrant, about 30 seconds. Add in mushrooms with more salt and cook for about 5 minutes to soften.
- Reduce heat to medium-low, and add chicken broth and heavy cream to the skillet. Simmer the soup mixture, and add in xanthan gum, stirring often. Allow the sauce to thicken and simmer for 5-10 minutes, adjusting the seasoning to taste.
- Add the mushroom soup mixture, and toss with green beans to combine. Add the crispy topping to the top of the casserole, then bake, covered with aluminum foil for 25 minutes. Remove the foil, and continue to bake for another 10-15 minutes until the top is golden brown. Enjoy!
- Store in an airtight container in the fridge for up to 4 days. We don't recommend freezing.
Notes
- This recipe is a little on the higher end of carbs for a keto diet, although it's much better than using store-bought cream of mushroom soup. If desired, the carbs can be reduced by omitting the canned french fried onions. You can instead top it with crispy fried pork rinds to lower it to 5g of net carbs per serving!
- Add in xanthan gum slowly and stir frequently, a little bit goes a long way, and keep in mind that the sauce will thicken as it cools.
- Don't be shy about adding salt to the water for boiling the beans. You will need at least 3 tablespoons of kosher salt.
- Don't overcook the green beans. The idea is for the green beans to still have a lot of "snap" to them before they go into the oven, where they will continue to soften.
Nutrition
These nutrition facts are provided as a courtesy and are only estimates. We cannot guarantee the accuracy.
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