This roasted cauliflower gratin recipe was inspired by a craving for macaroni and cheese and the desire for something a little healthier. I combined my favorite roasted cauliflower with lots of cheese and a delicious breadcrumb topping, similar to potato gratin.
It has all the indulgent flavor of a classic gratin but with a veggie-forward spin that makes it a little healthier and just as satisfying. Whether you’re planning a holiday menu, hosting a dinner party, or simply craving something cheesy and cozy, this cauliflower gratin will be a new favorite!
What is a Gratin?
You know those crispy, golden bits of baked cheese or sauce left around the edge of a casserole dish? In my family, we always fight over them. Apart from being called delicious, there’s actually a French word for it: gratin.
The term comes from the French verb gratter, meaning to scrape, because in 16th-century France, nothing went to waste. Every last browned bit was scraped from the pan. Over time, “gratin” came to describe a dish with a bubbly, browned top layer, usually created by broiling with cheese or breadcrumbs.
One of the most famous examples is gratin dauphinois, made with thinly sliced potatoes and cream. However, gratins can be made with almost anything, including vegetables, like my broccoli Idaho potato gratin and roasted butternut squash gratin, pasta, or even fruit for a sweet version.
This Roasted Cauliflower Gratin is my modern take on the French classic. Featuring roasted cauliflower tossed in a creamy cheese sauce, baked until golden, and finished with a crispy breadcrumb topping, it’s cozy, cheesy, and the perfect side dish for holidays or weeknights!
Ingredients and Notes
Please be sure to scroll down to the recipe card for the complete details!
- Fresh Cauliflower – You’ll need 2 ½ pounds of cauliflower florets for this recipe, which is about one large head of cauliflower. Save time by buying pre-chopped cauliflower, if desired. I don’t recommend using frozen cauliflower, or it’s likely to be soggy!
- Olive Oil – This coats the cauliflower, adding good-for-you fats and helping it caramelize in the oven.
- Butter – This forms the base of the cheese sauce, creating a rich flavor. Use dairy-free butter if you want to keep your cauliflower gratin dairy-free.
- Flour – All-purpose flour thickens the cheese sauce. Substitute a 1:1 all-purpose gluten-free flour or potato starch if you need to keep this recipe gluten-free.
- Milk – I use low-fat milk to keep this recipe a little lighter, but any regular or plant-based milk will work.
- Cheese – Sharp, shredded cheese creates a bold, savory taste. Parmesan cheese or Gruyère makes for a good substitute, if preferred. For the best results, buy a block of cheese and grate it yourself. Pre-shredded varieties contain anti-caking agents that prevent them from melting as nicely.
- Breadcrumbs – I use Panko breadcrumbs, but any breadcrumbs or crushed crackers work well.
How to Make a Roasted Cauliflower Gratin Recipe
- Roast the cauliflower. Toss the cauliflower florets with oil, and spread them in an even layer on a baking sheet. Roast until caramelized and fork-tender, stirring after about ten minutes to prevent burning.
- Create the sauce. In the meantime, melt the butter in a saucepan over medium heat, and whisk in flour, salt, and pepper to form a thick paste or roux. Slowly whisk in the milk, adding a little bit at a time.
- Thicken. Heat until the mixture thickens and bubbles around the edges, stirring frequently. Be careful not to let it boil! Whisk in the cheese, allowing it to melt completely. Then, reduce the heat, and stir frequently until you’re ready to assemble the cauliflower gratin.
- Layer. Spread the roasted cauliflower in an even layer in a baking dish, and pour the cheese sauce evenly on top. Sprinkle the breadcrumbs evenly over the cheese.
- Bake. Transfer the baking dish to the oven, and bake just until the edges begin to brown and the cheese sauce is bubbly.
- Broil. Preheat the broiler, and broil the dish for just a few minutes until the top is browned to your liking. Enjoy!
Tori’s Top Tips for Success
- Roast, don’t steam. Roasting prevents watery cauliflower and adds caramelized flavor.
- Use strong cheese. Sharp cheddar, Gruyère, or a cheddar-Parmesan mix works best.
- Don’t walk away from the broiler. It only takes a minute to turn golden brown.
- Add a little spice. A pinch of cayenne, smoked paprika, or nutmeg in the cheese sauce takes the flavor to a new level of deliciousness.
Roasted Cauliflower Gratin
Ingredients
- 2 1/2 pounds cauliflower florets (about one large 3 lb cauliflower head)
- 1 tablespoon olive oil
- 2 tablespoons unsalted butter
- 2 tablespoons flour
- 1 teaspoon salt
- 1/4 teaspoon black pepper
- 1 1/4 cups lowfat milk
- 3/4 cup shredded sharp cheddar cheese, tightly packed
- 3 tablespoons breadcrumbs (I used Panko)
Gluten Free/Passover Modification Ingredients
- 1 tablespoon potato starch
- 3 tablespoons parmesan cheese
Instructions
- Preheat oven to 425 degrees F. Spread out the florets on the baking sheet and drizzle with olive oil. Toss to coat (I usually use clean hands to make sure the cauliflower is evenly coated). Place them in the oven to roast for 10 minutes. After 10 minutes, stir the florets with a wooden spoon. Return to the oven and roast for about 15 minutes longer till the edges brown/caramelize and the cauliflower is tender.
- While the cauliflower roasts, in a medium saucepan, melt butter over medium heat. Whisk in the flour, salt, and pepper. Stir to form a thick paste.
- Slowly whisk in the milk, ¼ cup at a time. Heat the milk mixture over medium heat for a few minutes, whisking frequently, till it thickens and begins to bubble around the edges. Do not let the sauce boil.
- Whisk in the grated cheddar cheese and stir till melted. Reduce heat to lowest setting, stirring frequently, until ready to assemble the gratin.
- Remove roasted cauliflower florets from the oven and reduce oven temperature to 375 degrees. Place the roasted florets in an even layer in a 2 qt gratin dish or 8×8 inch baking dish.
- Pour the cheese sauce evenly across the top of the cauliflower florets.
- Sprinkle the breadcrumbs evenly across the top of the cheese sauce.Place the assembled gratin into the oven and bake for 20-30 minutes till edges begin to brown and the cheese sauce is bubbly.
- Remove the gratin from the oven and turn on your broiler. When broiler is hot, place the gratin back in the oven and let it brown under the broiler for 1-2 minutes, watching it carefully, till the top is browned to your liking.
- Serve hot. If you’re like to try a spicy modification on this recipe, substitute cayenne pepper for the black pepper, and add another pinch of cayenne to the sauce.
NOTES
Nutrition
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FAQs
This dish is extremely versatile. If you’re keeping kosher, it can serve as a lighter main dish or dairy side dish. It’s also great with seared salmon or poached fish filets. If you’re not worried about keeping kosher, it works well with a variety of roasted meats like honey herb roasted chicken, roast turkey, or braised beef brisket.
For a vegetarian meal, serve the cauliflower alongside black-eyed pea burgers or oven roasted root vegetables. On holidays, it fits right in with classic sides like slow cooker stuffing, olive oil mashed potatoes, and orange cranberry sauce.
Yes! You can assemble the gratin up to 24 hours in advance and refrigerate it, tightly covered. When you’re ready to bake, remove it from the fridge and let it sit at room temperature for 15–20 minutes. Then bake as directed, adding an extra five to ten minutes to account for the chill.
You can also bake the cauliflower gratin completely, refrigerate it for up to 3 days, and reheat it in the oven at 350°F until warm and bubbly.
ROASTED CAULIFLOWER GRATIN—- I have a family reunion shortly & plan to take this yummy recipe. . In order to save time, is it possible to roast & brown the cauliflower the day before, chill it over night for safety,then make the roux & finish it the next day? I need to get as much done the day before as possible. Thanks for any help…
Hi Patricia– yes, you can definitely roast the cauliflower ahead of time. The gratin may take slightly longer to bake through if the cauliflower is chilled straight from the fridge.
call me silly but I really appreciate that you always cite your recipes.
Not silly at all, in fact I appreciate that you noticed! A lot of research goes into these historical posts, and I always site my sources in case readers want to learn more on their own. It’s always best to give credit where credit is due. 🙂
I just made this recipe, and it was so yummy that my husband actually had to push the dish away so that he would stop eating it! The only change I made was to separately roast a pint of grape tomatoes, mixing them in with the roasted cauliflower right before adding the cheese sauce. Between the golden top and the red tomatoes, it was a very pretty dish.
Hi, I am new to your site and love it! I love cauliflower as well and I do mine a little different, this comes from my father who is a Hungarian Jew. I put the slightly cooked CF in a baking dish and smother it in butter, sour cream (or yogurt/kefir if you are trying to be healthy) and the top it with bread crumbs then I bake it till the top gets brown. It is amazing and so not healthy but very addictive!!!
This looks amazing. Do you think it would be as tasty if I roasted the cauliflower ahead of time? Would it work to make the sauce too, ahead of time, and then assemble right before guests arrive? I would like to prep as much in advance as possible.
Hi Sarah, you can definitely roast the cauliflower ahead of time, but I would make the sauce just before you assemble it… it’s the type of sauce that will get thick and lumpy if you make it ahead. It only takes a few minutes to make the sauce, it’s super easy. Good luck! Let me know how you like it. 🙂
This might be the only way I would eat cauliflower. It looks delicious!!!! 🙂
That looks incredible! I am lucky, always the first to get at that crusty cheese portion 🙂
I love that you first roasted the cauliflower until browned and gorgeous before smothering it in cheese sauce and baking it off. I could seriously fantasize about this gratin!
Can this be used with frozen cauliflower? Please say yes. It’s looks delicious.
Kosher_girl, absolutely– but you won’t be able to roast the cauliflower. Roasting frozen vegetables can turn them into a mushy disaster because they have too much moisture in them. Instead, skip the roasting step. Steam the frozen cauliflower on the stovetop till just tender, but not soft (tender-crisp). Then proceed with the recipe by placing the cauliflower into the gratin or baking dish and covering with sauce. Good luck!
This looks yummy! How would you change the recipe for frozen cauliflower? Thanks!
Hi Talya! See my response to Kosher_girl for the answer to your question. 🙂
Hi Tori – so neat to see that antique salamander. The only ones I’ve ever seen are the modern type, in restaurant kitchens.
I was roasting cauliflower this week too.
Your dish sounds delicious (as always).
LL
wow, that’s what I call comfort food! Must be so delish!
im first gen. american of British parents that came to America after WWII …Cauliflower Au gratin was a staple in my home as a child it was a common side with the sunday roast and was eaten thru the week as a leftover…..my favorite was with a sunny up fried egg and a dash of hot sauce on toast for breakfast…..
a great alternative to the Cauliflower is to use Leeks instead of roasting them off saute them til just starting to brown up i also like to add Cottage Cheese and Feta to the sauce mix for a bit of extra cheesyness….
So many great things to do w/ cauliflower. Just roasted then a mixture of lemon juice, hot pepper flakes and olive oil stirred onto it is great. It makes a nice kugel w/ an almond-herb crust or cooked well, pureed, then shredded cheddar+sour cream or ricotta+grated parm stirred in. Yummm…
Thanks for the historical info, it’s always cool to know
Hi Shiksa, It’s so great to see one of your recipes at another site. I’m going to try this w/ broccoli instead. Hope all is well w/ you and yours, Tracy
This looks amazing! Can’t believe I never thought of this one on my own. I will be making this very soon – perhaps with salmon and asparagus…
How do you do that!!! How do you seem to know what is going to be in my Organic Veggie Coop bags!!! This time… four heads of cauliflower! rofl… Guess what I am making tonight.
A little bird told me, Ber! teehee
Wow! That looks great. How did it reheat? (If you had any left to reheat.) Seems like it might be a great Shabbat afternoon dish during these long summer Saturdays!
Hey Amanda! Yes this is a great Shabbat dish, and it reheats very well. Just pop it in the oven at 325 degrees F for 10 minutes or so till heated through. You can also microwave it to reheat. Enjoy!
Thanks for the gratin lesson! haha. I’ll be sure to try this 🙂
hi i’m just wondering if when you put the sauced cauli back into the oven to bake, is it still at 425? or lower?
thanks
In the recipe instructions you’ll note that it says to reduce heat to 375 degrees F before putting back in.