Recipe: Broccoli & Cauliflower Gratin

updated Jan 29, 2020
Broccoli and Cauliflower Gratin
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(Image credit: Nealey Dozier)

I’m a sucker for all of the holiday food coverage that comes this time of year. I do have to admit though, I never actually attempt any of the new recipes that come my way. I happen to be a Thanksgiving traditionalist, and come Turkey Day all I want are the familiar dishes of my youth.

(Image credit: Apartment Therapy)

This year my boyfriend and I are joining our families for a communal celebration. As excited as I am to merge our many traditions, it also means that we have to pick food favorites. Who’s stuffing is best? My mom’s or his. Should we make his family’s cherished chocolate pie recipe or mine? Trust me, I’m really not looking forward to choosing teams.

Upon thinking about it further, however, I realized it might be a fine opportunity to experiment with a few new dishes. There will be so many other classics on the sideboard that if a new recipe isn’t a hit, it just won’t make an appearance next year. But if it’s a success? Then we’ve got a new holiday tradition. I really can’t lose.

I thought I’d start with a classic dish that appears on many American holiday tables, but has never showed up on mine: I took the idea of a traditional broccoli casserole and gave it a little update. This vegetable gratin replaces canned “cream of” soup with a cheesy, creamy Mornay sauce. It’s then topped with a crumb topping, and baked until bubbly and golden brown. Upon first tasting, I just can’t imagine it not being a total success come Thursday. In fact, this homemade casserole has already made it into my comfort food hall of fame.

How about you? Do you experiment with new recipes on Thanksgiving or stick to the standards?

(Image credit: Apartment Therapy)

Broccoli and Cauliflower Gratin

Serves 8

Nutritional Info


  • 2 pounds


  • 2 pounds

    cauliflower (about 1 large head)

  • 4 tablespoons

    unsalted butter, divided

  • 1

    small sweet onion, diced

  • 2 cloves

    garlic, minced

  • 1/4 cup

    all-purpose flour

  • 2 cups

    whole milk, scalded

  • 1 cup

    grated Gruyère cheese

  • 1/2 teaspoon

    mustard powder

  • 1/2 cup


  • 1/4 cup

    grated Parmigiano-Reggiano cheese

  • 1 tablespoon

    olive oil

  • Kosher salt and freshly ground pepper, to taste


  1. Preheat oven to 350°

  2. Bring a large pot of water to a boil. Cut off the woody bases of the vegetables and tear or chop into bite-sized florets. Add the vegetables to the water and cook until the broccoli is bright green, about 1- 2 minutes. Drain and place in an ice water bath to stop the cooking. Set aside in a large mixing bowl.

  3. In a large oven-proof skillet or braising dish, melt 1 tablespoon of butter over medium heat. Add the onions and sauté until soft and translucent, about 5 min. Add the garlic and cook for an additional 30 more seconds. Remove the onion mixture and set aside with the vegetables.

  4. Wipe out the skillet and melt the remaining 3 tablespoons of butter over medium heat. Whisk in the flour and cook until the mixture is smooth, about one minute. Pour in the milk and continue to cook, whisking frequently until the sauce is thickened. Turn off the heat; stir in the Gruyere and mustard powder until the cheese is melted and the sauce is creamy. Season generously with kosher salt and pepper.

  5. Pour the cheese sauce over the vegetables and toss to combine. Season again, to taste. Add the vegetables back to the skillet. Mix together the panko, Parmesan, and olive oil. Sprinkle over the vegetables and bake until hot and bubbly, about 40 minutes. If crumbs are not dark enough cook them under the broiler for 1 - 2 minutes until golden brown.

Recipe Notes

Note: this can be served with hot cooked rice as a vegetarian entree. I think this would also taste great made with cheddar cheese.

(Image credit: Apartment Therapy)

(Images: Nealey Dozier)