Cauliflower au gratin takes cauliflower to the next level, turning it into a creamy, cheesy casserole bursting with flavor. Tender cauliflower pieces are coated in a velvety cheese sauce, creating a comforting dish that comes together in under an hour using everyday pantry staples.
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This cauliflower side dish is a great way to jazz up a vegetable, just like my Honey Garlic Roasted Carrots and my Parmesan Roasted Brussel Sprouts with Bacon.
Why This Cauliflower Gratin Recipe Works
The creamy cheese sauce makes the not always appealing cauliflower become a desired side dish that has the whole family, adults and kids alike, reaching for seconds.
You only need a handful of ingredients and some herbs and spices to whip this dish up.
This side dish is easy enough to use for a weeknight side dish or fancy enough for a holiday dinner, just like my Garlic Parmesan Roasted Cauliflower.
Just like Potatoes au Gratin, the flavorful cheese sauce really makes this easy, creamy cauliflower au gratin a true belly warming, comfort food dish.
Gather the ingredients
- Veggies: Fresh cauliflower florets and chopped onions
- Olive oil: Avocado oil can also be used.
- Dairy: Butter, milk, cream cheese, shredded gruyere cheese and shredded sharp cheddar cheese
- Herbs and spices: minced garlic cloves, dry mustard, salt, and black pepper
- All purpose flour: Helps to thicken the cheese sauce.
How to make Cauliflower Au Gratin
- Step 1: Prep and rinse your cauliflower. Break florets into easy-to-eat, bite size pieces and place on your baking sheet. Toss with olive oil before roasting in a preheated oven until fork tender.
- Step 2: Add butter and diced onion to an oven-safe skillet. Cook until onions are soft. Add in garlic and cook until fragrant.
- Step 3: Add flour to the mix and cook.
- Step 5: Add milk to the pot and whisk until smooth, let simmer.
- Step 5: Add the mustard powder, salt, pepper, and cream cheese to the pot and whisk until the cream cheese is melted and everything is mixed together.
- Step 6: Add some of the shredded cheese to the pot and whisk to melt the cheese.
- Step 7: Remove roasted cauliflower from the oven and transfer to the cheese sauce pot.
- Step 8: Add the rest of the shredded cheese and transfer the skillet to the oven to finish baking until hot and bubbly. Salt and pepper to taste.
Recipe Tips
- Store this easy cauliflower gratin leftovers in an airtight container in the refrigerator for up to 3-4 days. You can reheat using the microwave, in a baking dish in the oven, or in a saucepan on the stovetop.
- For an even creamier sauce, I like to use blocks of cheese and shred it as I am using it. The pre-shredded cheese doesn't melt as easily as fresh shredded cheese when making this cheesy sauce.
- Add a bit of extra crunchy texture by adding Panko breadcrumbs or regular bread crumbs on top to bake until golden brown, during the last few minutes of baking for the perfect side dish.
- Instead of just cauliflower, you could use a mixture of broccoli and tender cauliflower florets, or just use all broccoli.
- Instead of using Gruyere cheese, you can swap it out for various other options. Try mozzarella cheese, Jack cheese, more cheddar cheese, some whole milk mozzarella or even some shredded Swiss cheese.
Recipe Faq's
If you end up with watery cauliflower recipes, this is typically because you have overcooked your cauliflower. If you overcook cauliflower it can become soggy and can water down the creamy sauce.
Yes, you can make this cauliflower bake ahead of time. Once it's fully baked, you can let it cool to room temperature before covering with the skillet lid or plastic wrap and storing it in the fridge until later. Then when ready, pop it in a casserole dish or keep it in the oven-safe skillet and reheat until warmed through.
I prefer to use fresh cauliflower, but you could use frozen if needed. If choosing to use frozen, thaw it first and strain out any extra water. I'd still roast it to get the cauliflower nice and tender, but you could skip the roasting step if needed.
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Cauliflower Au Gratin
Equipment
- 1 skillet
Ingredients
- 8-10 cups cauliflower florets
- 2 tablespoon olive oil
- 4 tablespoons butter
- 1 cup chopped onion
- 2 cloves garlic minced
- 2 tablespoon all purpose flour
- ½ teaspoon dry mustard
- ½ teaspoon salt
- ¼ teaspoon black pepper
- 1 ½ cups milk
- 4 ounces cream cheese
- 1 1/2 cups shredded gruyere cheese
- 1 cup shredded sharp cheddar cheese divided
- Salt and pepper to taste
Instructions
- Preheat the oven to 400 degrees. Rinse the cauliflower and break into 1 ½ inch bite sized pieces. Place on a baking sheet and toss with olive oil until coated.
- Bake for 12-15 minutes or just until fork tender.
- Heat an oven safe skillet on medium high heat and add the butter, diced onions and cook just until soft about 2-3 minutes, Add in the garlic and cook another 30 seconds until fragrant.
- Sprinkle in the flour and cook about 1-2 minutes to cook the flour a bit.
- Whisk in the milk until smooth, bring to a simmer and reduce heat to low.
- Whisk in the mustard powder, salt, pepper and cream cheese. Simmer on low until cream cheese is melted.
- Whisk in the shredded cheese reserving ½ cup of cheddar for the top.
- Add in the roasted cauliflower and toss until coated. Top with remaining cheese and bake for 15-20 minutes. Or until hot and bubble.
- Add more salt and pepper to taste if needed.
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