This delicious cauliflower au gratin keto casserole is surprisingly easy to make. And with the rich sauce plus the cheese and bacon on top, you’ll never even miss the potatoes!

Article Index
I’m always looking for hearty side dishes to serve around the holidays. But this cheesy cauliflower dish is so tasty, I find myself whipping it up year round!
It helps that it’s so easy to throw together. Simple sides free up your time and energy so you can focus on the rest of your meal.
To make cauliflower au gratin keto friendly, just combine broth with cream and spices for the sauce. Mix it with the cauliflower and cheese, top with bacon and more cheese, and toss it in the oven to bake!
This casserole turns out so hearty and delicious, you’ll never even miss the potatoes. It's similar to my ham and cauliflower casserole which has been a family favorite for year.
How to make cauliflower au gratin keto
Cauliflower is a great substitute for starchy, high-carb potatoes. And by making the easy sauce ourselves, we can eliminate most of the carbs you find in traditional au gratin.
- Make the cream sauce. Combine broth, cream, garlic, onion powder, poultry seasoning, and xanthan gum (or glucomannan) in a medium saucepan. Cook over medium heat until thickened then remove from heat.

- Assemble in baking dish. In a casserole pan, add the cauliflower, cheese, and prepared sauce. Mix until well-combined. Sprinkle bacon on top, then cover with more cheese.

- Bake the low-carb cauliflower gratin. Place in the oven and bake at 350°F until the top is browned and the cauliflower is tender.
Once the dish is ready, cut into 10 slices to serve!
If you don’t have poultry seasoning, you can substitute a mixture of sage, marjoram, thyme, parsey, and paprika instead.

Getting the right texture
To keep cauliflower gratin keto but still make a satisfying casserole, you need a thick sauce.
I found that adding a touch of low carb thickener helps to get that perfect consistency. When I first made this recipe, I used xanthan gum without any problems.
Unfortunately, some xanthan gum products can add a slimy texture. It all depends on what brand you use.
That’s why I prefer to use glucomannan as my sauce thickener these days. It seems to have a more consistent effect across brands. You can use either low carb thickener based on your preferences.
The other key is making sure that the casserole isn’t too soupy. That’s why I recommend using fresh or frozen cauliflower that has been cut into florets or slices. Riced cauliflower may release too much liquid into the casserole.
To save time, I like to buy pre-cut cauliflower. It’s always nice to avoid an extra step!

Other Recipes to Try
Looking for more low-carb side dishes to serve around the holidays or to round out a delicious meal? Check out a few of these favorites:
- My Keto Creamed Spinach Recipe is packed with so much cheesy flavor, even the kids will be asking for seconds!
- Roasted Radishes have the right flavor and texture to make them a great low-carb replacement for potatoes.
- Gluten Free Green Bean Casserole uses bacon, cheese, and wholesome ingredients for healthy, full flavor. No canned soup in this recipe!
- Pumpkin Casserole comes with a delicious herb topping that will pair beautifully with your holiday turkey or ham.
- Pan Fried Brussels Sprouts with Bacon is so delicious, even friends and family that dislike brussels sprouts might fall in love!

Cauliflower Gratin Recipe
I love how easy it is to make this side dish. It’s definitely a holiday favorite in our family because of its amazing flavor.
Plus, once you try this recipe, you will be amazed how simple it is to throw together! You only need five main ingredients plus spices and a thickener. Plus, prep takes 10 minutes or less.
And it’s a good thing, too, because everyone is going to be begging you to make this low carb cauliflower gratin! Even non-keto friends and family love this casserole.
It’s so rich, creamy, and cheesy, who could blame them?
Follow us on FACEBOOK, PINTEREST, and INSTAGRAM for even more tasty keto-friendly recipes!
Recipe

Cauliflower Au Gratin - Gluten Free
Video
Ingredients
- 14.5 ounces chicken bone broth
- ¾ cup heavy cream
- 4 cloves garlic minced
- ½ teaspoon onion powder
- ¼ teaspoon poultry seasoning see note
- 1 teaspoon xanthan gum or glucomannan
- 32 ounces frozen cauliflower florets or 2 fresh heads cut into florets
- 16 ounces freshly grated sharp cheddar cheese divided (or preferred cheese)
- 8 slices no sugar bacon cooked and chopped
Instructions
- Combine broth, heavy cream, garlic, onion powder, poultry seasoning, and xanthan gum in medium saucepan.
- Cook liquid over medium heat, stirring frequently, until thickened. Remove from heat.
- Mix the cauliflower, cheese, and sauce together in 9x13 casserole pan.
- Sprinkle the chopped bacon on top then cover with remaining cheese.
- Bake in 350°F oven for 50 minutes or until browned and cauliflower is tender.
Notes
Low Carb Sweeteners | Keto Sweetener Conversion Chart
Nutrition
Additional Info
Notes on Nutritional Information
Nutritional information for the recipe is provided as a courtesy and is approximate only. We cannot guarantee the accuracy of the nutritional information given for any recipe on this site. Erythritol carbs are not included in carb counts as it has been shown not to impact blood sugar. Net carbs are the total carbs minus fiber.
Copyright
© LowCarbYum.com - Unauthorized use of this material without written permission is strictly prohibited unless for personal offline purposes. Single photos may be used, provided that full credit is given to LowCarbYum.com along with a link back to the original content.
First Published: November 20, 2015... Last Updated: August 6, 2020
Susan Siemers
This took quite a while to make, lots of ingredients. I convert to metric. Recipe says 56.7 g cauliflower florets. That is about 3 florets! Obviously wrong. 32 oz. is 907 g. not 56.7. So now I am not trusting anything in there! It seemed like there wasn't enough sauce. Your program for converting seems to be off. I will give this one more try using US measurements instead of metric. I did obviously check out the amount of cauliflower. But what else might be off? It's in the oven, very unsure of what I am going to get with all of the time it took to make this. Also, I followed recipe in email I received, says it serves 5, but this recipe is pretty much the same, says it will serve 12. Love your recipes, but this one needs some cleaning up!! Thanks
Lisa MarcAurele
So sorry about that! I do rely on a program to convert and I'll take a look at this one again. Hope it worked out despite the conversion.