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. But this one is better for you AND tastes better!
Ahhhh green bean casserole. Such a tradition at Thanksgiving, 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 healthy keto 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 classic green bean casserole). 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.
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 crunchy onions without all the added ingredients. And perfect for a gluten-free green bean casserole.
Did you know that Campbell's Soup is actually the inventor of the green bean casserole?
History of recipe. The green bean casserole was 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 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 make 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 green bean casserole 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.
- green beans - check out the section above about which green beans to choose
- white mushrooms - 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
- Make the homemade condensed cream of mushroom soup sauce.
- Thaw or steam your green beans.
- Mix together the homemade condensed cream of mushroom soup and the green beans in the casserole dish. This is when you can season it to taste with salt, pepper, or other spices of your choice.
- Stir together the topping ingredients and sprinkle on top. Bake in the oven at 350 for about 25 minutes until it is hot and the topping is golden.
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.
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.
- 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.
- 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.
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. This is a great way to get more topping on there without increasing the number of carbs.
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.
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 and pop into the fridge but keep the topping separate and add that right before baking.
More Keto Side Dishes
I have a great list of other healthy side dishes that you can also make ahead. Just like this healthy green bean casserole, they taste better when you make them a day or two before and heat them up!
- Preheat oven to 350.
- Mix together the finely chopped mushrooms, sour cream, mayo, and spices. Fold in the green beans. Spread in an 8 x 8 baking dish.
- Mix the topping ingredients. Sprinkle over the green beans.
- Bake for 25-30 minutes until hot, bubbly, and the topping is golden brown.
Originally Published Revised November 9, 2018. Revised and Republished September 3, 2021.