This easy Roasted Cauliflower Gratin recipe features roasted cauliflower baked in a creamy cheese sauce. This is a delicious side dish special enough for holidays but easy enough for every day.
This post was originally published in January 2021 and has been updated with additional information.
Roasted Cauliflower Gratin (or Au Gratin) combines the wonderfully nutty-like flavor of roasted cauliflower with a crave-worthy cheesy cream sauce.
Roasting brings out an almost nutty flavor in the cauliflower, and I love the crisp-tender texture and the slightly charred edges.
The addition of a cheesy, creamy au gratin sauce takes roasted cauliflower to the next level.
What is a gratin?
A gratin or (French gratin) is a casserole of vegetables baked in a Bechamel (cream) sauce. 'Gratin' refers to the crusty top that forms while baking, typically from cheese and/or bread crumbs added to the top of the casserole.
Why you will love this dish
Any recipe that is baked until bubbly and golden brown is my kind of dish.
- Easy to make - The sauce can be prepared while the cauliflower roasts. The preparation is minimal - cut the cauliflower into florets and shred the cheese. The other ingredients are likely already in your pantry or refrigerator.
- Lighter than traditional gratins - This isn't a low-calorie dish, but the sauce isn't as heavy or laden as traditional cheesy cream sauces. It's made with half milk and half vegetable broth - as compared to all milk or part milk and part cream as is common in most white sauces. The broth adds a nice balance of flavor and pairs well with the cauliflower.
- Lots of flavor - Most gratin recipes call for parboiling the cauliflower. I prefer to roast the cauliflower. Roasting enhances its flavor and creates delicious caramelized edges. Also, all of the nutrients stay in the cauliflower when roasted.
Cauliflower - When buying cauliflower, look for white, firm heads with compact florets and fresh leaves. Avoid ones that have brown blemishes on the florets.
Vegetable broth - The broth adds another layer of flavor and contributes to a lighter cream sauce. If you don't need this recipe to be vegetarian, chicken broth can be used instead.
Gruyère cheese - Gruyère is a popular cheese for gratins. It melts well and has a wonderful nutty flavor. Gruyère can be found in the gourmet cheese section of most supermarkets. If you have trouble finding Gruyère, Swiss cheese can be used.
Fontina cheese - Fontina is not traditional in gratins, but I love the creaminess it adds. It melts beautifully and has a mild flavor.
How to make cauliflower gratin
- Cut the cauliflower into florets and transfer them to a sheet pan. Toss with olive oil, salt, and pepper, and roast at 450 degrees for 12-15 minutes until slightly charred around the edges.
- For the cream sauce, melt the butter in a saucepan and add the flour. Whisk to combine and cook for 1-2 minutes to cook the raw flavor out of the flour. Season with pepper and a pinch of nutmeg.
- Slowly add the milk and the broth, whisking to incorporate. Cook for 3-4 minutes until slightly thickened.
- Add half of the Gruyere and Fontina cheeses, whisking while the cheese melts. Add the remaining Gruyere and Fontina cheese, whisking until melted and combined. Remove from the heat and whisk in the Parmesan cheese.
- Transfer the roasted cauliflower to a shallow baking dish. Pour the sauce over the cauliflower. Bake for 15-20 minutes until bubbly and golden around the edges. Serve warm.
- Use freshly shredded cheese for the best flavor and best melting quality. Pre-shredded cheese contains additives that prevent it from melting well.
- Roasting the cauliflower before assembling the gratin adds another layer of flavor to this dish.
- Pair this gratin with turkey tenderloins, pork tenderloin, beef, or chicken.
Yes, this dish can be made ahead of time. After combining the roasted cauliflower and cheese sauce in the baking dish, let it cool, then cover and refrigerate until you are ready to bake. Allow 5-10 minutes of additional baking time.
This dish pairs beautifully with many entrees. Serve with beef roast, pork tenderloin, or roasted chicken. It would also be delicious with salmon, shrimp, or scallops.
For best results, I do not recommend freezing cauliflower gratin. Cauliflower has a high moisture content, and the texture may become mushy after freezing. Also dairy can separate after freezing, so the cheese sauce may not have as desirable of a consistency. It's best to eat any leftovers within 3-4 days.
Try these roasted vegetable recipes next
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Roasted Cauliflower Gratin
- 1 head cauliflower (cut into florets)
- 1-2 tablespoons olive oil
- salt and pepper
- 2 tablespoons unsalted butter
- 2 tablespoons all-purpose flour
- ⅛ teaspoon black pepper
- pinch ground nutmeg
- 1 cup milk
- 1 cup low-sodium vegetable broth
- 4 ounces Gruyere cheese (shredded)
- 2 ounces Fontina cheese (shredded)
- ¼ cup Parmesan cheese (grated + extra for topping)
- parsley (for garnish)
- Preheat the oven to 450 degrees.
- Add the cauliflower florets to a sheet pan. Drizzle with olive oil and season with salt and pepper. Toss to coat. Roast for 12-15 minutes until the cauliflower is slightly charred and golden around the edges. Remove from the oven and reduce the heat to 375 degrees.
- Meanwhile, make the sauce. Add the butter to a saucepan set over medium heat. Once melted, whisk in the flour until combined. Cook for 1-2 minutes to cook out the raw flour taste. Whisk in the black pepper and nutmeg.
- Slowly add the milk and vegetable broth, whisking to incorporate. Cook for 2-4 minutes until thickened slightly.
- Add ½ the Gruyere and Fontina whisking to incorporate while the cheese melts. Repeat with the remaining half of the cheese. Once melted, whisk in the Parmesan and remove from the heat.
- Transfer the roasted cauliflower to a pie dish or shallow casserole. Pour the sauce over the top. Bake at 375 degrees for 15-20 minutes until bubbly and golden around the edges. Serve warm.
- Use freshly shredded cheese for the best flavor and melting quality.
- To make ahead of time: after combining the roasted cauliflower and cheese sauce in the baking dish, let it cool, then cover and refrigerate until you are ready to bake. Allow 5-10 minutes of additional baking time.
- For best results, I do not recommend freezing cauliflower gratin. Cauliflower has a high moisture content, and the texture may become mushy after freezing. Also dairy can separate after freezing, so the cheese sauce may not have as desirable of a consistency. It's best to eat any leftovers within 3-4 days.
- This cauliflower dish pairs well with beef, chicken, turkey, pork, and seafood.
Nutritional information is an estimate and will vary depending upon the exact amounts and specific ingredients used.