Keto Green Bean Casserole

Keto Green Bean Casserole is a creamy, comforting side with tender green beans and a crisp, cheesy topping. It uses my homemade keto cream of mushroom soup instead of canned condensed soup and skips breaded French-fried onions.

This low carb green bean casserole is perfect for Thanksgiving, Christmas, or any dinner that needs an creamy vegetable side. I make it with fresh green beans, but canned and frozen green beans also work when you need a convenient option. For a full holiday plate, serve it with pressure cooker turkey breast, keto cornbread dressing, and keto cranberry sauce.

Why You’ll Love This Recipe

• Homemade mushroom sauce: Fresh mushrooms, onions, broth, and heavy cream make it rich and creamy without flour or cornstarch.
• Crunchy pork-free topping: Parmesan crisps and roasted pecans add crunch without breaded onions or pork rinds.
• Easy to adjust: You can use fresh, frozen, or canned green beans.
• Perfect for the holidays: It is an easy keto-friendly and gluten-free alternative to traditional green bean casserole.

Ingredients Needed

• Fresh green beans: I buy washed and trimmed green beans in a steam-in-bag package to save time. You can microwave them in the bag or use a steamer basket.
• Keto cream of mushroom soup: My homemade version uses cremini mushrooms, sliced onions, broth, seasonings, and heavy cream.
• Mozzarella cheese: I use low-moisture shredded mozzarella so it melts without adding too much liquid.
• Parmesan cheese crisps: These replace the breaded French-fried onions and form the base of the crunchy topping.
• Roasted pecans: These add extra crunch and a lightly nutty flavor.
• Dried parsley, garlic powder, and onion powder: These season the topping. The Parmesan crisps are already salty, so you usually will not need extra salt.

How to Make Keto Green Bean Casserole

Cook the Mushroom Soup Until Creamy

Sauté the mushrooms and onions until they are soft and most of the liquid from the mushrooms has cooked away. The finished soup should look creamy and lightly coat a spoon.

Steam the Green Beans Until Tender

Microwave washed and trimmed green beans in their steam-in-bag package or use a pot with a steamer basket. Cook them until tender enough to eat but still slightly firm since they will soften a little more in the oven.

Pulse the Topping into Coarse Crumbs

Add the Parmesan crisps, pecans, and seasonings to a food processor or blender. Pulse a few times, leaving some larger pieces for extra crunch.

Bake Until Golden and Bubbling

Stir the green beans into the mushroom soup and transfer the mixture to a baking dish. Add the mozzarella and crunchy topping, then bake until the edges are bubbling and the top is golden brown.

Tips for the Best Results

• Let the sauce thicken: If the mushroom soup looks thin, simmer it for a few more minutes before adding the green beans.
• Cook the beans before assembling: The casserole does not bake long enough to cook raw green beans, so they should already be tender.
• Taste before seasoning: The broth base, mozzarella, and Parmesan crisps all add salt, while the herb seasoning includes pepper.
• Watch the topping: The casserole is ready once the filling is hot and the topping is browned.

Can I Make Low Carb Green Bean Casserole with Canned or Frozen Green Beans?

Yes. Fresh green beans give the casserole the firmest texture, but canned and frozen green beans both work.

Canned Green Beans

Choose no-salt-added or low-sodium green beans when possible. Drain and rinse them well, then let the excess water drip away before folding them into the mushroom soup. Canned beans are already tender, so you do not need to steam them first. The finished casserole will have a softer texture than one made with fresh beans.

Frozen Green Beans

Frozen green beans often come in microwaveable steam bags. Cook them until tender but still slightly firm, then drain them well before adding them to the soup. Pat them dry if they still seem wet so the extra water does not thin the sauce.

For a simpler green bean side, try my sautéed green beans, air fryer green beans, or roasted green beans.

Can I Use Canned Cream of Mushroom Soup?

I prefer the homemade keto cream of mushroom soup because it gives you fresh mushroom flavor and more control over the ingredients and thickness.

Most traditional canned cream of mushroom soups contain flour or other starches. Check the ingredient list and nutrition information before using one.

You can also make the homemade soup ahead of time. Reheat it in a large skillet, add the prepared green beans, and continue with the recipe.

Make Ahead and Storage

• Make ahead: Prepare the green bean mixture and add it to the baking dish with the mozzarella. Cover and refrigerate, then add the crunchy topping just before baking.
• Store: Keep leftovers in an airtight container or cover the baking dish tightly. Refrigerate for up to 3–4 days.
• Reheat: Warm individual servings in the microwave or reheat the casserole in the oven until hot. The oven will help the topping regain some crunch.

What to Serve with Green Bean Casserole

For a smaller holiday dinner, serve this casserole with air fryer turkey tenderloin or crockpot turkey tenderloin. Round out the meal with keto cornbread, keto creamed spinach, and keto gravy.

For an everyday dinner, try it with air fryer chicken legs, air fryer BBQ wings, air fryer chicken breasts, or Ninja Foodi pot roast.

You can find more menu ideas in my collections of keto holiday recipes and keto side dishes.

If you try this recipe, please stop back and leave it a star rating and/or a review in the comments. Stay connected & share photos of your creations with me & others on Instagram, Facebook, and Pinterest!