This cauliflower au gratin is super rich and ultra cheesy. It’ll become a family favorite in no time! Perfect for the holidays, the cauliflower is roasted for a delicious side dish that’s all creamy and not watery!
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What Makes This Recipe So Good
- This cauliflower au gratin is made of cauliflower smothered in tons of cheesy goodness and topped with rich, buttery breadcrumbs. It’s the perfect side dish for holidays or if you just want a new way to get your kids to eat veggies!
- With an easy first step to help remove moisture, the cauliflower in this recipe isn’t soggy or mushy, making the texture of this au gratin absolutely perfect.
- A couple easy swaps make this recipe gluten free, so it’s great if you’re serving it to guests or family members who are sensitive to gluten.
How To Make Cauliflower au Gratin
The full recipe & ingredients list are below, but here you’ll find a quick overview for making this recipe perfectly, along with useful tips and info!
Roast the cauliflower on a baking sheet to help remove some of the water.
In a small saucepan, heat some butter and add the onion, cooking until it becomes soft. Add the flour and stir constantly until it just starts to brown. Slowly pour in the milk and whisk until the sauce becomes smooth. Add plenty of salt and pepper and simmer.
Remove the sauce from the heat and stir in half of the cheese.
Add the cauliflower to a greased baking dish and pour the cheese sauce over. Sprinkle the rest of the shredded cheese on top.
Melt the rest of the butter and stir in the breadcrumbs and a pinch of salt.
Bake the cauliflower au gratin until the cheese is melted and brown. Sprinkle with the breadcrumbs and bake until bubbly. Sprinkle some parmesan on top and serve.
Top Tips For Making
- To make this cauliflower au gratin gluten free, swap the breadcrumbs for gluten free ones and the flour for gluten free all-purpose flour.
- You can use any type of shredded cheese for this recipe, but I absolutely love shredded cheddar. Gruyere is also a good option, as is swiss or white cheddar.
- Use fresh cauliflower instead of frozen. Frozen will make your cauliflower au gratin way too watery.
More Holiday Side Dishes
- Gluten-Free Stuffing
- Whole30 Green Bean Casserole (Paleo, Grain-Free, Dairy-Free)
- Asparagus Casserole
- Whole30 Crockpot Mashed Potatoes (Vegan)
- Instant Pot Whole30 Cranberry Sauce with Apples and Rosemary (Paleo, No Sugar)
- Ham Gravy
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Cauliflower au Gratin
- 8 cups cauliflower florets about 2 medium heads or 1 large, about 2 pounds in total
- 1 small onion chopped
- 6 tablespoons unsalted butter ½ stick, divided
- 4 tablespoons all-purpose flour
- 2 cups hot milk
- 1 teaspoon salt
- ½ teaspoon black pepper freshly ground
- 2 cups shredded cheese like Gruyere or cheddar
- ¼ cup parmesan freshly grated
- ¼ cup breadcrumbs
- Preheat oven to 375º F and grease a 9×9-inch or 2 quart baking dish. Place cauliflower on baking sheet and roast for 20 minutes. Heat 4 tablespoons butter in a small saucepan over low heat. Add onion and stir until softened, about 5 minutes.
- Add flour to saucepan and cook while stirring constantly until mixture just starts to brown, about 3 to 5 minutes. Gradually pour milk into mixture, whisking into a smooth sauce. Stir in salt and lots of pepper. Cook until just simmering. Remove sauce from heat and stir in half the shredded Gruyere or cheddar cheese until it melts.
- Place steamed cauliflower in the prepared baking dish and pour cheese sauce over.
- Sprinkle cauliflower and cheese sauce with remaining Gruyere or cheddar cheese and 1/4 cup parmesan, if desired. Melt remaining 2 tablespoons butter and stir together with breadcrumbs and a pinch of salt.
- Bake in the preheated oven until cheese is melted and browned, about 20 minutes. Remove from oven and sprinkle with breadcrumbs. Return to oven for 5-10 minutes or until bubbly. Sprinkle parmesan over with cheese after cooking and serve.
- Gluten free: Use gluten free breadcrumbs and gluten free all-purpose flour.
- Shredded cheese: We prefer cheddar, but Gruyere, swiss, and white cheddar are also good options.
- Cauliflower notes: Use fresh cauliflower instead of frozen. Frozen will make your cauliflower au gratin way too watery.
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Cheryl Malik is the recipe developer, writer, and photographer behind the healthy, flavorful, family friendly recipes at 40 Aprons. She’s been a blogger for 10+ years and is known for her delicious recipes and detailed recipe instructions. Cheryl is a mom of three who lives in Memphis, TN.