Keto Green Bean Casserole Recipe : Gluten-Free Low Carb (2024)

This healthy low carb Keto Green Bean Casserole is exactly what you need for your holiday meals. Creamy mushroom sauce and crunchy onion topping will remind you of the traditional green bean casserole with condensed soup and fried onion topping.

Classic green bean casserole. Such a tradition at Thanksgiving dinner, Christmas, Easter, potlucks, and other holiday meals in the US. I've been making it and eating it for as long as I can remember. I've thought about making my own low carb green bean casserole for years but wasn't exactly sure how to mimic the flavors of the condensed cream of mushroom soup AND the crunchy onion topping.

I had a reader email me her ideas for an easy low carb green bean casserole and I tried it and it was delicious. But it had cheese and bacon (two of my favorite ingredients, but not in traditional green bean casserole recipes). I've thought about sharing it a few times anyway but decided to wait on tradition and go for mushrooms and crunchy french fried onion topping instead in my keto version.

Last time I was in the grocery store I picked with a can of French's Crispy Fried Onions and looked through the ingredients. They are pretty much just onions and flour. But how could I make the same flavor and texture without all the work involved with actually breading and frying onion slices?

Enter dried minced onions. They are crispy onions without all the added ingredients. And perfect for a holiday season gluten-free green bean casserole.

Ingredients

Green beans - Fresh or frozen work fine. Using frozen simplifies the prep time.

White mushrooms - I use fresh mushrooms. Either white button mushrooms or baby bella mushrooms also work well.

Sour cream - I like the combo of sour cream and mayo in this but if you would like to make it dairy free you can use coconut cream in place of the sour cream.

Mayo - I normally use a canola based mayo but avocado oil mayo or soy mayo also work.

Dried minced onion - This is my secret ingredient for an easy topping similar to french fried onions.

Bouillon powder - I make my own and it is based on nutritional yeast so this dish is vegetarian.

Butter - I use salted butter in all of my recipes.

Almond flour - For a nut free dish you can sub in sunflower seed flour.

Salt & pepper - I give suggestions on the amounts to use but feel free to season to taste.

How to Make Keto Green Bean Casserole

This shouldn't take more than 10 minutes, tops. Since you are using dried minced onion it saves the step of cooking onions that I've seen in many homemade green bean casserole recipes.

Step One: Make the homemade condensed cream of mushroom soup sauce. Making the creamy sauce is as simple as stirring together the ingredients. No sauteing or cooking required.

Step Two: Thaw or steam your green beans.

Step Three: Mix together the sauce and the green beans in the casserole dish. This is when you can season the green bean mixture to taste with salt, pepper, or other spices of your choice.

Step Four: Stir together the topping ingredients and sprinkle on top of the casserole. Bake in the oven at 350 for about 25 minutes until it is hot and the topping is golden brown.

Tips

I have a couple of tips for you when making this keto green bean casserole from scratch.

Use frozen green beans - This saves time on having to steam fresh green beans.

Use frozen mushrooms - Mushrooms are not a vegetable that freezes well but they are much easier to finely chop (without making mushroom mush) when they are frozen. Simply pop your white button mushrooms in the freezer the day before making this. Then finely chop them in the food processor.

Long beans - If your green beans are very long cut them into bite-sized pieces. If they are very thick you can cut them in half lengthwise.

Make-ahead - This is a great make-ahead side dish! To make this ahead of time bake the green beans in the sauce without the topping. Cool and refrigerate. When you ready to serve just add the topping and bake again until the green beans are hot.

Variations

Crushed Pork Rinds - If you want to bulk up the crunchy topping you can mix in some crushed pork rinds before putting it on the casserole. Pork rinds work well in keto recipes. This is a great way to get more crispy topping on there without increasing the grams of carbs for a keto diet.

Cheese - If you normally add cheese to this dish go ahead and add some! Parmesan cheese, mozzarella cheese, or cheddar cheese all work well with the other flavors.

Bacon - Is bacon ever not wanted? Mix in some cooked crumbled bacon to the sauce for a pop of flavor.

Common Questions

Where did green bean casserole originate?

Did you know that Campbell's Soup is actually the inventor of the green bean casserole?

History of recipe. Thegreen bean casserolewas first created in 1955 by the Campbell Soup Company. Dorcas Reilly led the team that created the recipe while working as a staff member in the home economics department.

That is one way to boost sales of condensed canned soup! Sorry, Campbells I cut you out entirely of this recipe. But will give credit for the creation of this delicious holiday side dish. We really love it any time of the year. I made it along with my Garlic Parmesan Chicken Tenders the other day.

Should I Use Fresh or Frozen Green Beans?

Either will work for this keto recipe but it is easier to use frozen. If you use fresh green beans you need to boil or steam and drain them first.

I used frozen green beans from Costco and thawed them in the microwave before proceeding. Next time I think I will cut them in half because they were pretty long.

It can be awkward to try to get a long green bean in your mouth without cutting it and I don't want my holiday guests to need to cut their green beans if they are eating off of paper plates while sitting on my light natural colored couch.

In a pinch, you can use canned green beans but they are at the bottom of my list. Fresh or frozen cooked green beans taste much better.

Can I Make This Ahead?

Yup! This low carb keto green bean casserole can be made up to 2 days ahead. Just prep it in the baking dish of your choice covered with a lid or plastic wrap and pop into the fridge but keep the topping separate and add that right before baking for your Thanksgiving table.

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More Keto Side Dishes

I have a great list of other healthy side dishes that you can also make ahead. Just like this delicious green bean casserole, these low carb recipes taste better when you make them a day or two before and heat them up!

Keto Mashed Cauliflower with Cream Cheese

Keto Creamed Spinach

Garlic Broccoli

Keto Stuffed Mushrooms

Sugar-Free Cranberry Sauce

Originally Published Revised November 9, 2018. Revised and October 30, 2023.