Keto Green Bean Casserole
A creamy, comforting holiday classic made keto-friendly with fresh green beans, a from-scratch mushroom cream sauce, and crispy fried onions on top. At just 5.4g net carbs per serving and ready in 50 minutes, it's the side dish everyone will reach for.
Head of Nutrition · June 17, 2026
Nutrition per serving
Per serving · makes 8. Values are estimates; brands vary.
This keto green bean casserole delivers all the creamy, savory comfort of the Thanksgiving classic without the carb-heavy canned soup or breaded onions. Fresh green beans, a rich homemade mushroom cream sauce, and a crispy onion topping make it a side that earns its spot on any holiday table.
Ingredients
- 1.5 lb fresh green beans, trimmed and halved
- 8 oz cremini mushrooms, sliced
- 4 tbsp butter
- 3 cloves garlic, minced
- 1 cup heavy cream
- 4 oz cream cheese, softened
- 1/2 cup chicken or vegetable broth
- 1/2 cup grated Parmesan cheese
- 1/2 tsp salt, plus more for blanching
- 1/4 tsp black pepper
- 1/4 tsp xanthan gum (optional, for thickening)
- 1/2 medium yellow onion, thinly sliced
- 2 tbsp avocado oil, for frying onions
Instructions
- 1
Preheat oven to 375°F (190°C). Bring a large pot of salted water to a boil and blanch the green beans for 4 minutes, then drain and plunge into ice water to stop the cooking. Drain well and set aside.
- 2
Melt the butter in a large skillet over medium heat. Add the sliced mushrooms and cook for 6-7 minutes until golden and their liquid has evaporated. Stir in the minced garlic and cook 1 minute more.
- 3
Lower the heat and add the cream cheese, heavy cream, and broth. Whisk until smooth, then stir in the Parmesan, salt, and pepper. If the sauce seems thin, sprinkle in the xanthan gum and whisk vigorously, simmering 2-3 minutes until it coats the back of a spoon.
- 4
Fold the blanched green beans into the mushroom cream sauce until evenly coated. Transfer to a greased 9x13-inch baking dish.
- 5
Heat the avocado oil in a small skillet over medium-high heat. Fry the thinly sliced onion, stirring often, for 5-7 minutes until deep golden and crisp. Drain on a paper towel.
- 6
Bake the casserole for 18-20 minutes until bubbling around the edges. Scatter the crispy onions over the top and bake 2 more minutes. Let rest 5 minutes before serving.
Tips & notes
- For an even crunchier topping, toss the crispy onions with 2 tbsp crushed pork rinds before scattering over the casserole.
- Make ahead: assemble through step 4 up to a day in advance and refrigerate. Add 5-8 minutes to the bake time and fry the onions fresh before serving.
- Store leftovers in an airtight container in the fridge for up to 4 days. Reheat in a 350°F oven to keep the topping from going soggy.
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Frequently asked questions
- How many carbs are in keto green bean casserole?
- Each serving has 5.4g net carbs (7.9g total carbs minus 2.5g fiber), along with 218 calories, 5g protein, and 19g fat. This recipe makes 8 servings.
- Why is regular green bean casserole not keto?
- Traditional versions use canned cream of mushroom soup (thickened with wheat flour and often sugar) plus store-bought fried onions coated in wheat flour. Both push the carb count high. This recipe swaps in a from-scratch cream cheese and Parmesan sauce and pan-fried fresh onions to keep it low-carb.
- Can I make this green bean casserole dairy-free?
- Yes. Use full-fat coconut cream in place of the heavy cream, a dairy-free cream cheese alternative, and nutritional yeast instead of Parmesan. The texture will be slightly looser but still rich and creamy.
