This Cauliflower Au Gratin Recipe is rich, cheesy, and irresistibly delicious. Tender roasted cauliflower is layered with creamy Gruyère and Parmesan cheese, flavored with garlic, shallots, Dijon, and spices, and finished with crispy bacon. Crisp on top, tender in the center, and unbelievably rich, it’s a comforting side dish you’ll make again and again!
The BEST Cauliflower Au Gratin Recipe
Move over au gratin potatoes these cauliflower au gratin recipe is my new fav! The roasted cauliflower gives it a slightly nutty flavor that pairs perfectly with the Gruyère and Parmesan cheese sauce. Add in the bacon, garlic, and smoky paprika, and you’ve got a veggie-filled side dish that feels every bit as indulgent as the classic. Whether I’m serving it for a holiday feast or as a weeknight side, it always gets rave reviews, and I usually end up wishing I had made a double batch!
Ingredients You’ll Need
Cauliflower: You’ll need about 8 cups or 1 large head of cauliflower for this recipe. You can save time chopping by buying pre-chopped florets at your local grocery store, but make sure you get a large bag.
Olive Oil: This helps the cauliflower roast and caramelize in the oven.
Bacon: Adds smoky, salty flavor and crisp texture. The rendered drippings also enhance the base of the cheese sauce.
Garlic and Shallot: Sautéed until tender, these create a sweet, savory, pungent flavor base for the sauce.
Butter: Provides richness and combines with the cornstarch to create a thick sauce that clings to the cauliflower.
Cornstarch: Thickens the sauce without making it heavy.
Half and Half: Creates a luscious creamy base for the sauce without diluting the flavor.
Sour Cream: Adds a tanginess that balances the richness of the butter and cheese. It also adds the perfect creaminess.
Dijon Mustard: Adds subtle sharpness and lots of depth.
Seasonings: Dried thyme, nutmeg, smoked paprika, salt, and pepper add warmth and savoriness.
Cheese: Gruyère melts beautifully for a silky texture and nutty flavor, while Parmesan adds sharpness and helps create a golden, bubbly crust.
How to Make Cauliflower Au Gratin
Step 1. Toss the cauliflower with oil, salt, and pepper. Then, transfer it to a casserole dish, and roast until the edges begin to brown and the cauliflower florets are just tender.
Step 2. Next, cook the bacon until crispy in a large skillet over medium heat. Set aside to drain on paper towels, leaving drippings and a thin layer of grease to coat the pan.
Step 3. Add the butter, followed by the shallot and garlic, and cook until the aromatics are translucent. Stir in the seasonings and cornstarch.
Step 6. Then, whisk in the half and half, Dijon, and sour cream, and let the sauce simmer and thicken. Stir in the cheese, and adjust the seasonings to taste.
Step 5. Pour the cheese sauce evenly over the roasted cauliflower florets, and sprinkle the remaining cheese and bacon pieces on top.
Step 6. Bake until the cheese is melted and the sides are bubbly. Then, broil for just a few minutes to achieve a golden crust. Serve warm, topped with chives. Enjoy!
Ways to Serve
Serve this cauliflower au gratin recipe with all your favorite main courses! It makes for a delicious weeknight dinner alongside smash burgers, salisbury steak, or fried chicken tenders. Or, add it to your holiday table with roasted turkey, buttermilk fried chicken, and oven baked ham.
Can I Make Au Gratin Cauliflower in Advance
Yes! You can make this au gratin cauliflower recipe a day in advance to make your holiday prep a bit easier. To make this dish in advance, roast the cauliflower, fry your bacon, and make your cheese sauce. Then, store each separately in the refrigerator. Once you are ready to bake, assemble the au gratin as written and bake per the instructions.
How to Store and Reheat
Refrigerator: Let the au gratin cool completely, then cover it tightly with foil, or transfer it to an airtight container. Store in the fridge for up to 3-4 days.
Freezer: Technically, you can freeze leftovers for up to 2 months, but I don’t recommend it. The texture becomes mushy and slightly grainy once thawed.
Reheating: Warm leftovers covered in the oven at 350°F for about 15-20 minutes. Then, uncover and bake for another 5 minutes to crisp the top again. For smaller portions, you can also reheat in the microwave, but the oven will give you the best texture.
More Delicious Side Dishes
- Dirty Rice
- Roasted Brussel Sprouts with Bacon and Dates
- Buttermilk Biscuits
- Baked Mac and Cheese
- Candied Yams
- Butterbeans with Smoked Turkey
- Roasted Green Beans with Mushrooms and Crispy Onions
- Funeral Potatoes
I hope you love this Cauliflower Au Gratin Recipe! It’s rich, cheesy, and perfect for every occasion. If you do give this recipe a try, I want to know! Leave a comment with a star rating below. You can also snap a photo & tag @butterloveandsalt on INSTAGRAM. Your reviews help support Butter, Love & Salt and make it possible for me to continue to create delicious recipes.
Cauliflower Au Gratin with Gruyère and Bacon
Ingredients
- 1 large head cauliflower cut into florets (about 8 cups)
- 1 tablespoon olive oil
- 4 slices bacon cut into pieces
- 1 shallot
- 4 tbsp unsalted butter
- 3 cloves garlic minced
- 2 tablespoon cornstarch
- 2 cups half and half
- 1/2 cup sour cream room temperature
- 1 tablespoon Dijon mustard
- 1/2 teaspoon dried thyme
- 1/8 teaspoon nutmeg
- 1 tsp salt
- 1/4 tsp black pepper
- 1/4 tsp smoked paprika
- 1/2 cup + 2 tbsp parmesan cheese divided
- 1 1/2 cup gruyere cheese divided
Instructions
- Preheat an oven to 425F degrees. Toss the cauliflower florets in olive oil and liberally season with salt and pepper. Transfer them to a 9×13 casserole dish and roast for 22-27 minutes until the edges start to brown and the cauliflower florets are just tender. Once the cauliflower is done, reduce the heat to 400F degrees.
- Next, make the cheese sauce. Start by cooking the bacon over medium heat in a large skillet. Cook until crispy and then remove from the skillet to drain on paper towels. Drain the excess bacon grease from the skillet, leaving any drippings and only a thin layer of grease to coat the pan.
- Next, add the butter. Then, add the shallot and garlic to the skillet and cook until the shallot becomes translucent, around 3-4 minutes. Next, add the thyme, salt, pepper, nutmeg, and smoked paprika. Then, stir in the cornstarch starch until well combined. Cook for about 1 minute.
- Whisk in the half and half, dijon mustard, and sour cream. Then, let the sauce simmer until thickened, around 5-10 minutes. Then, stir in 1/2 cup of the shredded parmesan cheese and 1/2 cup of the gruyere cheese. Taste the cheese sauce and adjust seasoning for taste (I typically add 1/2-1 tsp more salt).
- Pour the sauce evenly over the roasted cauliflower florets. Top with reserved 1 cup shredded gruyere cheese and crispy bacon. Pro tip. I add most of the cheese; then, I add the bacon, and, then, the rest of the cheese.
- Bake the casserole at 400 degrees until the cheese is melted and the sides are bubbly, around 10-15 minutes. Then, Broil the casserole for 1-3 minutes to achieve a golden crust. Once done, let the au gratin cool slightly before serving. Garnish with chives and enjoy!
Nutritional Information
Recipe by: Chavez Adams / Butter, Love & Salt | Photography by: Meg McKeehan.
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