Cheesy Broccoli and Cauliflower Gratin Recipe

Cauliflower Gratin is an easy side dish you’re sure to love! This Cheesy Broccoli Cauliflower Recipe is absolutely delicious. Be sure to add Cauliflower Broccoli au Gratin to your holiday table!

broccoli and cauliflower gratin in a baking dish

Broccoli and Cauliflower Gratin

Cauliflower Gratin is cheesy, creamy, and easy to make. You’re going to love this cauliflower broccoli au gratin recipe for Thanksgiving, Christmas, Easter, and more!

Everyone loves Potatoes Au Gratin, but you can use this same technique on all kinds of dishes. I’ve shared Brussels Sprouts Gratin in the past (such a tasty dish), as well as Three Cheese Asparagus Gratin and even Creamy Spinach Gratin. Now I’m sharing my Cheesy Broccoli and Cauliflower Gratin!

Cauliflower is the go-to vegetable when you need something to replace starchy potatoes. Luckily, you can replace a lot of potato dishes with this super veggie (like mashed cauliflower) when you want to cut down on carbs and create a healthier version of your favorite recipes. Throw in some broccoli and you’ve got a cheesy and delicious side dish for any occasion.

I love this broccoli cauliflower recipe because it’s so simple yet so full of flavor. The cheese sauce is the real star of the show! Add it to your holiday table or make it alongside your favorite chicken recipes. Either way, it tastes amazing!

This CHEESY Broccoli Cauliflower Gratin recipe is the perfect side dish for holidays and weeknight dinner!


overhead view of cauliflower broccoli au gratin

close up on cheesy broccoli and cauliflower recipe

How to Make Broccoli and Cauliflower Gratin

This recipe only takes about 30 minutes from start to finish! That’s the kind of recipe I like. And yes it’s covered in cheese, but it’s filled with broccoli and cauliflower, so I’m going to call it healthy (ish) and feel really good about eating it!

Here’s the basic process:

  1. Make the breadcrumb topping by chopping up the bread in a food processor.
  2. Cut cauliflower and broccoli into small florets, and boil them for about 3-4 minutes to soften them up slightly.
  3. Make the cream sauce by combining and cooking all sauce ingredients in a skillet.
  4. Stir the cauliflower, broccoli, and cheese into the cream sauce.
  5. Pour the broccoli/cauliflower/sauce mixture into the baking dish and sprinkle the bread crumbs on top.
  6. Bake for 15-20 minutes at 425°F.

It will come out hot, creamy, cheesy, bubbly, and a little bit crispy thanks to the breadcrumb topping. Yum! Check the recipe card at the bottom of this post for more detailed instructions.

Recommended Products to make Cauliflower Broccoli au Gratin

a plate of broccoli cauliflower casserole next to a full casserole dish

overhead view of creamy broccoli and cauliflower dish

Can you freeze cauliflower gratin?

You can freeze this broccoli and cauliflower gratin if you want to prepare it ahead of time or just save leftovers. I wouldn’t recommend this as something to freeze since it will change the texture of the broccoli and cauliflower, but it is definitely doable. Just cover the dish and freeze as you would a casserole. Then let it thaw in the refrigerator and bake when you’re ready to eat.

a plate of cauliflower broccoli gratin

plate of broccoli and cauliflower gratin viewed from above

Easy Broccoli and Cauliflower Recipes

Cauliflower and broccoli are two of the best vegetables when it comes to variety. You can boil them, steam them, saute them, bake them, and you can combine them with just about any ingredient. There are so many delicious broccoli and cauliflower recipes out there, but here are a few favorites for you to try:


Best Easy Holiday Recipes for Thanksgiving, Christmas, and more


casserole dish filled with cauliflower and broccoli with a bread crumb topping

Cheesy Cauliflower Broccoli Au Gratin is such a great veggie side dish. What’s not to love about vegetables covered in cheese?! Nothing. I can’t wait for you guys to try this!

See the recipe card below for details on how to make Cheesy Broccoli Cauliflower Gratin. Enjoy!


If you like this cauliflower broccoli au gratin, try these other delicious side dishes:

5 from 5 votes
Cauliflower Gratin is an easy side dish you're sure to love! This Cheesy Broccoli Cauliflower Recipe is absolutely delicious. Be sure to add Cauliflower Broccoli au Gratin to your holiday table!
Cheesy Broccoli and Cauliflower Gratin Recipe
Prep Time
10 mins
Cook Time
20 mins
Total Time
30 mins
Cauliflower Gratin is an easy side dish you're sure to love! This Cheesy Broccoli Cauliflower Recipe is absolutely delicious. Be sure to add Cauliflower Broccoli au Gratin to your holiday table!
Course: Side Dish
Cuisine: American
Keyword: broccoli cauliflower gratin, cheesy broccoli, cheesy cauliflower, gratin recipe
Servings: 8
Calories: 326 kcal
Author: Becky Hardin
For the Bread Topping:
  • 3 slices whole wheat or white sandwich bread a little dry is best (*SEE NOTE)
  • 2 tablespoons butter softened
  • ¼ teaspoon table salt
  • 1/8 teaspoon freshly ground black pepper
For the Cauliflower/Broccoli filling:
  • 1 tablespoon table salt
  • 1 medium head cauliflower about 1½ pounds (**SEE NOTE)
  • 1 head broccoli about 1 pound (**SEE NOTE)
  • 2 tablespoons unsalted butter
  • ¼ yellow onion diced (about 2 tablespoons)
  • 1 clove garlic minced
  • tablespoons all-purpose flour
  • cups heavy cream
  • ¼ cup low-sodium chicken broth or dry white wine
  • 2 pinches freshly grated nutmeg
  • 1 teaspoon dry mustard
  • 1 teaspoon crushed red pepper flakes
  • 1/8 teaspoon freshly ground black pepper
  • 1/2 cup grated Parmesan cheese
  • 1 cup shredded Sharp Cheddar cheese
  • Kosher salt to taste
  1. Heat oven to 425°F and set the oven rack to middle position.
  2. Spray a 2-quart (11x7) casserole dish with nonstick cooking spray.
For the Bread Topping:
  1. Tear each slice of bread into 4 pieces.
  2. Place the bread, butter, salt, pepper and herbs in a food processor fitted with the metal blade. Process until coarse crumbs form, about ten 1-second pulses. Set aside.
For the Cauliflower/Broccoli filling:
  1. Trim the cauliflower and broccoli into ¾-inch florets. If using broccoli stalks, use only ½-inch of stalk next to the floret.
  2. Fill a Dutch oven or stockpot 2/3rds full with water. Add 1-tablespoon salt and bring the water to a boil. Stir the boiling water and add the cauliflower and broccoli. Cook until the vegetables have a slight bite, 3-4 minutes and drain.
  3. Heat a large skillet over medium heat. Add butter and cook just until foaming subsides.
  4. Add onion and cook until softened and translucent, 2-3 minutes.
  5. Add garlic and cook 30 seconds.
  6. Sprinkle the flour over the onion/garlic mixture; stir and cook about 1 minute.
  7. Reduce the heat to medium-low and whisk in the cream and broth (or wine). While stirring, bring to a boil.
  8. Reduce heat to low and add nutmeg, salt, red pepper flakes, dry mustard, and black pepper. Cook (and stir) just until mixture has thickened a little.

  9. Add both cheeses and stir until cheese is melted.
  10. Remove from the heat and add the cauliflower and broccoli; stir gently to coat the vegetables
  11. Transfer cauliflower/broccoli mixture to the prepared dish and sprinkle with the breadcrumb topping.
  12. Bake at 425°F for 15-20 minutes or until the sauce bubbles around the edges and the top is golden brown. Serve immediately.
  13. Enjoy!

Recipe Video

Recipe Notes

*Note: If  you prefer, you can use 3/4 cups store bought Italian Bread Crumbs instead of dry bread

**Note: You can also use frozen broccoli and cauliflower. If using, use one bag of each and cook in the microwave according to package instructions. Pat dry before stirring into the cheese sauce. I like the steam fresh kind best.

Nutrition Facts
Cheesy Broccoli and Cauliflower Gratin Recipe
Amount Per Serving
Calories 326 Calories from Fat 225
% Daily Value*
Total Fat 25g 38%
Saturated Fat 15g 75%
Cholesterol 83mg 28%
Sodium 1235mg 51%
Potassium 533mg 15%
Total Carbohydrates 15g 5%
Dietary Fiber 4g 16%
Sugars 3g
Protein 10g 20%
Vitamin A 27.3%
Vitamin C 125.5%
Calcium 22.3%
Iron 7.2%
* Percent Daily Values are based on a 2000 calorie diet.
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