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Keto Green Bean Casserole

This easy, keto casserole recipe features fresh green beans baked in a creamy, dairy-free mushroom sauce, topped with homemade crispy fried onions. A healthy twist on a classic holiday favorite! Whole30, Gluten Free, Paleo, & Low Carb
Course Side Dish
Cuisine American
Prep Time 15 minutes
Cook Time 45 minutes
Total Time 1 hour
Servings 8 people
Calories 247kcal
Author Mary Smith


  • 2 lbs green beans ends chopped
  • 8 oz cremini mushrooms chopped
  • ½ large onion diced
  • 3 cloves garlic, minced
  • 1 tbsp ghee
  • 1 tbsp sherry omit for Whole30
  • 1 cup chicken broth
  • 1 tsp dried thyme
  • 1 tsp sea salt more to taste
  • ½ cup full fat coconut milk stirred before measuring - it separates in the can
  • ½ cup raw unsalted cashews
  • 1 tbsp fresh squeezed lemon juice
  • ½ cup water

Homemade Fried Onions

  • 1 large onion sliced in half and then cut into 2-3 inch pieces
  • 2 tbsp ghee
  • 2 tbsp avocado oil or coconut oil
  • 2 eggs beaten
  • 2 tbsp tapioca flour
  • ¼ cup coconut flour or fine almond flour
  • 1 tsp garlic powder
  • ½ tsp sea salt
  • ½ tsp paprika


  • Preheat oven to 375. Grease a 9x13 in casserole dish. Fill a large pot with water and bring to a boil. Add the green beans and boil for 5 minutes until crisp tender. Drain and set aside.
  • Heat up the tbsp of ghee in a large skillet. Add in diced onion, garlic, and mushrooms. Sprinkle with a bit of salt and pepper. Saute and let them cook for 7-8 minutes, stirring occasionally, until the mushrooms have sweat off some of their liquid. Add in the sherry (if using) and use a spoon to scrape the brown bits from the bottom of the pan. Add in the chicken broth, thyme, and sea salt. Bring to a boil, then reduce heat to medium low. Let it simmer while you make the coconut cashew cream.
  • Combine the coconut milk, cashews, lemon juice, and 1/2 cup of water in a blender. Blend on high for 1 minute until very thick and creamy.
  • Pour the cream into the pan and stir for 1-2 minutes. It should thicken fairly quickly. Taste it to see if you want to add more salt. You can use the sauce as-is, or use an immersion blender to break down the mushrooms a bit. It is up to you!
  • Add green beans to the casserole dish and pour the mushroom sauce on top. Stir to combine. Bake for 20 minutes.
  • Make the fried onions (if not using store-bought): Beat eggs in a shallow dish. Add tapioca flour, coconut (or almond) flour, garlic powder, salt, and paprika to a separate shallow dish and stir to combine. Heat the ghee + cooking oil in a large skillet over medium heat. Dip the onion pieces into the egg, and then into the flour mixture to coat. Fry them for 2-3 minutes each side or until they are browned to your liking. Transfer to a paper towel-lined plate to drain. Work in batches until all onion pieces have been fried.
  • When the timer goes off, add the fried onions to the top of the casserole (you may have some leftover - but they make a yummy snack!), and cook for an additional 10 minutes. Serve and devour!


If you're not worried about Whole30, you can save time and use store-bought fried onions. If gluten free, Check Whole Foods for their 365 brand Gluten Free Crispy Onions! Aldi also has a GF version, as well. 


Calories: 247kcal | Carbohydrates: 19g | Protein: 7g | Fat: 18g | Saturated Fat: 8g | Polyunsaturated Fat: 2g | Monounsaturated Fat: 7g | Trans Fat: 1g | Cholesterol: 55mg | Sodium: 581mg | Potassium: 534mg | Fiber: 5g | Sugar: 6g | Vitamin A: 857IU | Vitamin C: 19mg | Calcium: 71mg | Iron: 3mg