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Low Carb Mashed Cauliflower Casserole

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Mashed cauliflower is mixed with cream cheese, butter, cream, garlic and horseradish sauce for an extra zip of flavor! Even if you’re not a huge cauliflower fan, I hope you’ll give this recipe for cheesy Mashed Cauliflower Casserole a try because I believe it will make you (or someone you love) a cauliflower convert.

Mashed cauliflower casserole in a dish with a spoon and some peas.

Better grab a big spoon. You’re going to LOVE this cheese mashed cauliflower casserole!

I adore how versatile cauliflower is. I almost always have it in my fridge.

Cauliflower is one of those magical vegetables that can be morphed into just about anything these days. However, my favorite way to eat it is in this Easy Cheesy Cauliflower Casserole.

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**Please Note – The printable recipe card with detailed instructions and complete ingredient measurements for making today’s low carb cauliflower casserole is available near the end of this post. 

Vertical title text collage of cheese mashed cauliflower casserole.

The ingredient list for making Mashed Cauliflower Casserole;

  • Fresh Cauliflower
  • Cream Cheese
  • Butter
  • Heavy Cream
  • Garlic
  • Parmesan Cheese
  • Prepared Horseradish
  • Fresh Lemon Juice
  • Frozen Peas
  • Salt and Pepper

Check out my latest Kudos Kitchen tasty BBQ side dishes recipe roundup.

I developed this recipe because we’d been following a keto eating plan in my household.

That said, I’ve served this dish to several people who aren’t following a keto plan, and also to one person who doesn’t enjoy cauliflower at all, and they all approved of this delicious and slightly zippy side dish. WIN!

Cheesy Mashed Cauliflower Casserole in a casserole dish with fresh cauliflower, cream, and butter in the background

Turn even cauliflower haters into cauliflower lovers with this recipe for Cheesy Mashed Cauliflower Casserole.

Why this easy cauliflower recipe works?

The main reason is that it’s super simple to make, and you can mash the cauliflower to your desired consistency.

For this recipe, I like to keep the cauliflower a little chunky, so it has more body than your typical mashed cauliflower side dish. But feel free to mash it to whatever fits your preference.

Since this dish is heavily laden with cheese, cream, and butter, the importance of the horseradish and fresh lemon juice at the end cannot be overstated!

The fresh lemon juice cuts through the richness of the other ingredients and balances the flavors of this mashed cauliflower casserole in a wonderfully delicious way, and the horseradish adds a little zip that wakes up the entire dish!

Can this cauliflower casserole be made in advance?

Yes! You can either make it and refrigerate it before baking, or make it, bake it, and refrigerate it.

How long will it keep in the refrigerator?

Cover it well, and this low carb cauliflower casserole will keep for up to 5 days in the refrigerator.

Can store-bought prepared cauliflower rice be used in this recipe?

Yes! For ease, it sure can.

If you’re using frozen cauliflower rice, make sure it is completely thawed before using, and if needed, squeeze out any additional water (just as you would when using frozen spinach).

Actually, that sounds really good too. Why not add some thawed frozen spinach into the mix (maybe like 1 cup)? I think the combo would be a real winner! I think I’m going to make it that way next time myself! 😉

Can this casserole be frozen?

Yes! Wrap it well for the freezer and it can be kept frozen for up to 3 months.

Important: If freezing after baking, cool it completely before wrapping and freezing.

How do I bake the casserole after freezing?

You can either thaw it completely and then bake it, uncovered, at 350-degrees for 30 minutes.

If baking from frozen, bake in a preheated 350-degree oven for 60 minutes, uncover, and continue baking for an additional 15 minutes or until completely heated through. 

Vertical Title text image of mashed cauliflower casserole

The easy instructions;

  • Cut or break the florets off the cauliflower head.
  • Discard the core and leaves.
  • Add the florets to a large bowl.
  • Cover with plastic wrap and microwave for 10 minutes until soft and tender.

How to make Easy Cheesy Mashed Cauliflower Casserole with Peas, photo tutorial.

  • Mash the florets to your desired consistency.
  • Add softened butter, cream cheese, garlic, and heavy cream.

How to make Easy Cheesy Mashed Cauliflower Casserole with Peas, photo tutorial.

  • Add fresh lemon juice, prepared horseradish, Parmesan cheese, salt, and pepper.
  • Stir well.

How to make Easy Cheesy Mashed Cauliflower Casserole with Peas, photo tutorial.

  • Add frozen peas and mix.
  • Add the mixture to a 1½ quart baking dish and bake in a preheated 350-degree oven for 25-30 minutes.
  • Serve hot.

How to make Easy Cheesy Mashed Cauliflower Casserole with Peas, photo tutorial.

Cheesy Mashed Cauliflower Casserole in a blue and brown casserole dish with a spoon.

This cheesy mashed cauliflower casserole will become a new family favorite, and you’ll never miss the carbs!

Cauliflower has been enjoying a complete surge of popularity over the past few years! I don’t know who cauliflower’s publicist is, but whoever it is, they sure are doing things right! 😉

Additional Cauliflower Recipes

Below you'll find other delicious and creative recipes using cauliflower.

Below is the printable recipe card for today’s cheesy mashed cauliflower casserole.

If you’ve enjoyed this recipe, and are anxious to give it a try, I’d appreciate if you’d take a moment to give this recipe some feedback by way of stars near the comment section at the end of this post.

Cheesy Mashed Cauliflower Casserole is mixed with cream cheese, butter, cream, garlic and horseradish sauce for an extra zip of flavor! -

Best Easy Cheesy Mashed Cauliflower Casserole with Peas

Renee - Kudos Kitchen
Cheesy Mashed Cauliflower Casserole is mixed with cream cheese, butter, cream, garlic and horseradish sauce for an extra zip of flavor! 
4.25 from 4 votes
Prep Time 15 mins
Cook Time 30 mins
Total Time 45 mins
Course Casseroles, Side Dish, Vegetables
Cuisine keto diet, low carb diet, Vegetables
Servings 8 servings
Calories 174 kcal


  • 1 head cauliflower, florets removed
  • 4 ounces cream cheese, softened
  • 3 tablespoons butter, softened
  • ¼ cup heavy cream
  • 2 cloves garlic, minced
  • 2 tablespoons prepared horseradish, or to taste
  • ½ cup shredded Parmesan cheese
  • 1 teaspoon fresh lemon juice
  • 1 cup frozen peas
  • 1 teaspoon coarse salt, or to taste
  • ½ teaspoon black pepper, or to taste


  • Preheat oven to 350 degrees.
  • Place the cauliflower florets in a large bowl. Cover the bowl with plastic wrap and microwave for 10 minutes on high, or until the florets are soft and tender. 
  • Mash the florets with a potato masher. Add the remaining ingredients. Mash and mix to your desired consistency.
  • Spoon the mixture into a 1½ quart baking dish which has been sprayed with cooking spray.
  • Bake in a preheated oven for 20-25 minutes. Serve hot.


Tools and equipment:
Chef's knife, cutting board, large bowl, plastic wrap, microwave, potato masher, cooking spray, wooden spoon, measuring spoons, measuring cups, 1½ quart baking dish 


Serving: 1servingCalories: 174kcalCarbohydrates: 8gProtein: 5gFat: 13gSaturated Fat: 8gCholesterol: 42mgSodium: 510mgPotassium: 301mgFiber: 2gSugar: 3gVitamin A: 625IUVitamin C: 43.3mgCalcium: 113mgIron: 0.7mg
Keyword Cheesy Mashed Cauliflower Casserole, mashed cauliflower recipe
Tried this recipe?Let us know how it was!

I sincerely hope you’ve enjoyed easy cauliflower recipe (which just happens to be keto and low carb) as much as I’ve enjoyed bringing it to you.

Cheesy Mashed Cauliflower Casserole in a round casserole dish with lemon and peas.

Should you have any questions or comments regarding today’s recipe or anything else you’ve seen on my site, please don’t hesitate to contact me directly or leave me a comment in the comment section below. It is always my distinct pleasure to get back to you with a reply just as soon as I possibly can!

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Recipe Rating


Saturday 15th of December 2018

Can you sub sour cream for the cream cheese


Saturday 15th of December 2018

Hi, Melissa! You can, but then I'd suggest leaving out the lemon juice. Since the sour cream already has a tangy acidic flavor, the lemon juice would be overkill (in my opinion). Also, the completed dish may be a tiny bit thinner in consistency, but it should be objectionable. Thanks for the question. Take care, Renee


Wednesday 20th of June 2018

My husband claims not to like cauliflower, but with this recipe, I have no doubt he will be in love in no time!!