Cheesy Brussels Sprout Casserole is a rich and hearty keto side dish. A delicious way to round out all of your holiday meals. This post is sponsored by Cabot Creamery.

Sometimes I forget that the holidays aren’t endless desserts and treats, and that we actually need proper sustenance too. I love holiday baking so much, I can be a little myopic sometimes, thinking it’s all cookies and cakes.
But when I come up for air from all the baking, I crave rich and satisfying meals. And foods that provide that comfort food feeling for the cold winter days.
This Brussels sprout casserole recipe has that comfort food feeling in spades. It’s creamy, hearty, and pairs perfectly with any main course. It’s delightfully cheesy too, with a top layer of Cabot Creamery’s unparalleled sharp cheddar.
Did I happen to mention that it also has bacon?
This is going to be one of our sides at Christmas, to pair with our traditional holiday rib roast. I am practically drooling just writing about it.

Extra Cheese, Please!
This cheesy keto casserole is made au gratin style, with plenty of cream, garlic, and sharp cheddar melted into a rich sauce that’s poured over sauteed Brussels sprouts. It’s then topped with crisp bacon and more cheddar, and baked until bubbly and melted.
Gratin recipes typically take flour to thicken the sauce, but I’ve found that if you start with heavy cream rather than milk, and whisk in some cheese to help thicken it, you don’t need any flour at all.
And you know by now that if I am reaching for sharp cheddar, it has to be Cabot. I spent 11 years of my life in Boston and Cabot Creamery is a beloved institution in New England. It’s a co-op too, which means that the 800 dairy farmers that make up the company actually own it.
I’ve had the good fortune to actually meet some of these farm families and see them in action. And the pride in their work and their product is visible in everything. I’d go so far as to say it’s even edible!

How to make Keto Brussels Sprouts Casserole
Now that I’ve sold you on this creamy, cheesy deliciousness, it’s time to tell you how to make it. Let’s get started!
- Cook the bacon. I like to chop my bacon prior to pan frying it, so that it crisps up more evenly. It also cooks much faster this way, saving you time and energy.
- Sauté the Brussels sprouts. You can add them right into the pan after cooking the bacon. Cook undisturbed for a few minutes so that they brown lightly, then toss and brown on the other side and transfer to a casserole dish.
- Make the sauce. This is a classic au gratin sauce, with garlic, and cream, and a touch of Dijon mustard for additional flavor. Then some of the shredded Cheddar is whisked into the sauce until it melts.
- Pour the sauce evenly over the sprouts in the pan. You want to have good coverage but don’t worry too much, as it all spreads and melds together during baking.
- Sprinkle on the bacon bits. Again try to do this as evenly as possible so that every bite has a bit of crunchy bacon.
- Sprinkle with the remaining sharp Cheddar. I used Cabot’s Extra Sharp but you have lots of great choices here. Try the Seriously Sharp for even more tanginess, or the Vermont Sharp for a slightly more mild version. Or try their Alpine Cheddar for a more Swiss cheese flavor. You really can’t go wrong here.
- Bake until golden and bubbly! This should only take 15 to 20 minutes. You want the Brussels sprouts to be softened but not mushy. Fork tender is perfect!

Can you make Brussels sprouts casserole ahead?
Got a busy holiday ahead of you and want to make a few dishes ahead? I get it!
This keto casserole heats up well enough, but I think it tastes best on the day it’s baked. What you can do is prep everything and put it all together, and then wrap it up tightly without baking. It will last in the fridge for up to two days.
Allow the casserole to come to room temperature before baking.
Bon Appetit!
More delicious keto casseroles
- Cauliflower Shepherd’s Pie
- Easy Chicken Broccoli Casserole
- Cheeseburger Spaghetti Squash Casserole
- Keto Enchilada Casserole
- Loaded Cauliflower Rice Casserole
- Low Carb Beef Stroganoff Casserole

Cheesy Brussels Sprout Casserole is a rich and hearty keto side dish. A delicious way to round out all of your holiday meals.
- 6 slices bacon chopped
- 1 lb Brussels sprouts trimmed and halved
- Salt and pepper
- 1 tbsp avocado oil
- 2 cloves garlic minced
- ½ cup heavy whipping cream
- 1 tbsp Dijon mustard
- 6 ounces shredded Cabot Extra Sharp divided
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In a large skillet over medium heat, cook the bacon until crisp. Use a slotted spoon to transfer to a paper towel lined plate. Remove all but 2 tablespoons of the bacon grease.
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Preheat the oven to 400F.
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Add the Brussels sprouts, sprinkle lightly with salt and pepper, and cook until nicely browned, tossing occasionally, 5 to 7 minutes. Transfer the sprouts to a medium casserole dish and sprinkle with the cooked bacon.
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Add the avocado oil to the pan and sauté the garlic until fragrant, about 30 seconds. Stir in the cream and Dijon and whisk to combine. Cook 2 minutes to thicken, then stir in 2 ounces of the cheddar and whisk until melted. Add salt and pepper to taste.
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Pour the sauce evenly over the sprouts in the pan and sprinkle the top with the remaining cheddar. Bake 15 to 20 minutes, until the cheese is bubbly and browned.
Nicole says
This was AMAZING!
Janice says
So delicious! This is going to be one of my all time favorites. We even had it as a main dish tonight.
I forgot to replenish my bacon supply but I had a jar of bacon grease in my fridge and I substituted bacon bits for the bacon. It was just as tasty. We love the Cabot cheddar, too!
Joni says
What is cabat cheese and where do you get it?
Carolyn says
It’s a brand of cheese. you can click the link.
Hope says
We had this with a steak for dinner last night. Delicious and perfect! Thanks.
Carolyn says
So glad you liked it!
LeeAnn Pilati says
Can EvEO be substituted for the avocados oil ?
Carolyn says
Sure!
Sheri says
This was great…I love it!