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keto green bean casserole
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5 from 1 vote

Keto Green Bean Casserole

This Keto Green Bean Casserole is your favorite holiday side dish, lightened up a bit with fewer carbs and a homemade cream of mushroom soup.
Prep Time15 mins
Cook Time1 hr
Total Time1 hr 15 mins
Course: Side Dish
Cuisine: American
Servings: 14 people
Calories: 189kcal
Author: Briana


  • stock pot
  • large bowl
  • casserole dish (9x13 inch or larger)



  • 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)


  • 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.


  • 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.


Calories: 189kcal | Carbohydrates: 12g | Protein: 2g | Fat: 15g | Saturated Fat: 8g | Polyunsaturated Fat: 0.5g | Monounsaturated Fat: 2g | Trans Fat: 0.1g | Cholesterol: 27mg | Sodium: 507mg | Potassium: 243mg | Fiber: 2g | Sugar: 3g | Vitamin A: 786IU | Vitamin C: 9mg | Calcium: 42mg | Iron: 1mg