This cauliflower gratin recipe is crazy good comfort food! Tender pieces of steamed cauliflower get baked in a creamy and savory sauce flavored with Gruyere and garlic. The whole dish gets topped with cheesy, buttery breadcrumbs and baked until golden brown and bubbly.
Table of Contents
Why This Recipe Works
We’re not the biggest fans of cheesy-coated vegetable, but this cauliflower gratin recipe is different. It features quality cheese (Gruyère and Parmesan) and keeps the rest of the flavors relatively simple. Cayenne adds some heat while grated fresh nutmeg highlights the flavors of the cheeses. And finally, thyme and garlic add some welcome savorines to bring it all together. It is truly the perfect side dish recipe!
One large head is ideal. Seek out one that’s at least 2 pounds in weight. If you’ve got extra cauliflower, make this Cauliflower and Potato Caesar Salad.
We recommend using whole milk for this recipe. Anything lower in fat won’t be as delicious, and anything higher in fat will be a bit too decadent.
We keep the spices simple in this recipe! Just a dash of grated fresh nutmeg and cayenne pepper is all you need. If you want to up the ante a bit, consider adding a dash of smoked paprika and fresh thyme to the cheese sauce.
Our cheese sauce uses two types of cheese for the best balance of flavors! You’ll need Gruyère and Parmesan. Gruyère can be found in the specialty cheese section. It’s savory and nutty. Parmesan cheese can also be found in the specialty cheese section. We recommend getting a block and shredding it yourself.
Panko Bread Crumbs
If you can’t find it, we love to use whole-wheat Panko instead of regular. It adds a lovely toasty flavor. If you have regular Panko, you can use that too.
Test Kitchen Tips
- Instead of cooking the cauliflower in a large pot of boiling salted water, simply add the florets to a large glass bowl with a splash of water and a quarter teaspoon of salt. Plate a dinner plate over top or cover with plastic wrap. Microwave on high for 2 minutes. Check the tenderness and continue microwaving in 1 minute increments until crisp tender. Easy! Then just add the drained cauliflower to the cheese sauce.
- If you can’t find Gruyère cheese or would prefer something a bit more economical, use a sharp aged Cheddar cheese instead.
- Steam or blanch the cauliflower florets (we like to steam in the microwave because it’s quick and easy).
- Cook the onions and garlic in butter until softened.
- Whisk in the flour, salt, pepper, cayenne, and nutmeg and cook 2 minutes, whisking constantly.
- Gradually whisk in the warmed milk and cook, whisking constantly, until the sauce has thickened.
- Remove the sauce from heat then stir in the Gruyère cheese and half of the Parmesan until melted.
- Add the cauliflower and toss with the cheese sauce to coat.
- Transfer the cauliflower to a baking dish or casserole dish.
- Mix together bread crumbs, melted butter, half of the Parmesan and thyme. Sprinkle the breadcrumb topping over the au gratin.
- Bake cauliflower au gratin until golden brown and bubbly.
You can use more Parmesan or try using a sharp Cheddar. Aged Gouda would also be delicious.
I would not make the entire dish ahead of time, but you can prep the components. Steam the cauliflower and make the cheese sauce up to 3 days ahead of time. On the day-of, reheat the cheese sauce on the stovetop in a saucepan over low heat. Toss the sauce with the cauliflower and finish the dish per the recipe instructions.
Absolutely! To make this gluten-free, use gluten-free Panko and use a gluten-free flour blend for the roux. We have found sorghum flour is a great thickener for roux recipes as well.
Try adding some crispy bits of bacon or swap out some cauliflower for broccoli florets. You can also make this into a main dish by adding some shredded chicken, ham or turkey (great use of Thanksgiving leftovers!).
Watch How to Make It
Cauliflower Gratin with Gruyere & Thyme
- 1 large head cauliflower (2-2 ½ pounds), cut into 1-inch florets
- 4 tablespoons unsalted butter, divided
- 1 cup diced onion
- 2 large cloves garlic, minced
- 3 tablespoons all-purpose flour or regular whole-wheat flour
- Kosher salt and black pepper
- ½ teaspoon freshly grated nutmeg
- ¼ teaspoon cayenne pepper
- 1 ½ cups whole milk, warmed
- ½ cup shredded Gruyère (2 ounces)
- ½ cup shredded Parmesan (2 ounces), divided
- ½ cup whole-wheat Panko breadcrumbs
- 2 teaspoons chopped fresh thyme, or 1 teaspoon dried
- Preheat oven to 425°F (218ºC). Coat a 2-quart baking dish with nonstick spray.
- Place cauliflower florets in a large glass bowl. Add 1 tablespoon water and ¼ teaspoon salt; toss to coat then place a large dinner plate over top (or cover tightly with a piece of plastic wrap). Microwave for 2 minutes, stir and continue to microwave in 1 minute intervals until crisp-tender, about 4–5 minutes total*. Drain and set aside.
- Melt 2 tablespoons butter in a large sauté pan over medium heat. Add onions and garlic and cook until softened, about 5 minutes.
- Whisk in flour, ½ teaspoon each kosher salt and black pepper, nutmeg, and cayenne and cook, whisking constantly, 2 minutes.
- Slowly whisk in milk until thickened, 2 minutes. Off heat, stir in Gruyère and ¼ cup Parmesan, then stir in cauliflower until completely coated; transfer to prepared baking dish.
- Melt remaining 2 tablespoons butter. Combine melted butter with Panko, remaining ¼ cup Parmesan, and thyme; season with salt and black pepper. Sprinkle crumbs evenly over gratin.
- Bake until crumbs are golden brown and sauce is bubbly, 25–30 minutes. Let gratin rest 10 minutes.
- If you do not want to microwave the cauli, you can blanch it. Cook cauliflower in a pot of boiling salted water until crisp-tender, 2–3 minutes; drain.
- This recipe is adapted from a recipe I originally developed for Cuisine at Home Magazine
- The microwave time will largely depend on how powerful your microwave is. Check the tenderness of the cauliflower every minute or so to ensure it isn’t getting over-steamed.
This recipe article was originally published on November 11, 2021.