Cheesy Broccoli Cauliflower Casserole
Cheesy Broccoli Cauliflower Casserole is a cozy, creamy, golden-topped bake that turns two humble vegetables into true comfort food. It’s the perfect holiday side dish but easy enough for a weeknight.
There is something wildly comforting about a casserole that knows exactly what it wants to be — rich, cheesy, creamy, and unapologetically cozy. This Cheesy Broccoli Cauliflower Casserole is THAT dish. It’s the one that always disappears first at holiday dinners. It’s the one people ask for the recipe for on the drive home. And it’s the one that will convert even the most “meh” vegetable-eaters into “is there more of this?” believers.
I'm using two vegetables here on purpose — broccoli for flavor and color, cauliflower for body and silkiness. They roast into tender little bites that soak up the cheese sauce like sponges. Speaking of cheese: we’re not sprinkling a handful and calling it good. We’re folding in a generous amount into the sauce that wraps every edge of every floret. Creamy. Savory. Indulgent. Balanced by veg so you don’t feel wrecked after.
Make it as a Thanksgiving side, a Sunday dinner hero, or a “Wednesday needed this energy” main. Leftovers — if they exist — reheat like a dream.
Jump to:
Why You'll Love This Recipe
- Make Ahead Friendly - you can easily prep this entire casserole ahead of time, and pop it into the oven once you're ready to bake!
- Crowd Pleaser - even veggie-skeptical people go back for seconds, thanks to the creamy sauce, gooey cheese, and crispy breadcrumb topping.
- Flexible Recipe - you can switch up the cheese, the veggies, and the topping. Head to the Variations section for specific ideas.
- Perfect for a Holiday Meal - this easy casserole side dish goes perfectly with a Thanksgiving turkey, Christmas roast, or an Easter ham.
Ingredients
Broccoli - adds color, flavor, and a classic “cheesy broccoli” vibe that everyone loves.
Cauliflower - makes the casserole extra creamy + substantial without feeling heavy.
Butter - the fat that the onion and garlic are cooked in, and gives the cheese sauce silky richness.
Onion and Garlic - aromatics that add a ton of flavor to this cheesy casserole.
Cream of Chicken Soup - my secret ingredient for making this casserole super easy and creamy. I like to use organic Pacific cream of chicken soup. They also have a great cream of roasted garlic and herb soup, if you want to keep this recipe vegetarian .
Sour Cream and Mayonnaise - these also lend to the creaminess of the casserole.
Milk - or heavy cream, just to thin out the sauce a little.
Cheddar Cheese - I start with a block of cheddar cheese and shred it with my food processor.
Bread crumbs - for that crispy topping.
Please refer to the recipe card for the complete list of ingredients.
Variations
Switch Up the Type of Cheese - use sharp cheddar for classic comfort, Parmesan cheese and gruyère for fancy holiday vibes, pepper jack for a gentle kick, or smoked gouda to make it taste like it came off a wood fire.
Add Protein - stir in diced ham, cooked chicken, or crisp bacon bits before baking.
Different Topping - I like using garlic herb breadcrumbs but you can use panko, crushed Ritz crackers, or even some crispy fried onions.
Extra Vegetables - this casserole would be delicious with steamed carrots, corn, and green beans.
Step by Step Instructions
Photo 1. Melt butter in a medium pan over medium-high heat. Add the diced onion and cook until softened, about 5-7 minutes.
Photo 2. Add the garlic and cook another minute.
Photo 3. Place the broccoli and cauliflower florets in a microwave safe bowl. Add ¼ cup of water and cover with plastic wrap. Microwave for 5 minutes to steam the vegetables. You could also do this on the stovetop with a steamer basket.
Photo 4. In a medium bowl, whisk together the cream of chicken soup, mayonnaise, sour cream, milk and salt.
Photo 5. Mix the creamy mixture together with the vegetables.
Photo 6. Stir in the cheese.
Photo 7. Spread the vegetables out in a greased 9x13" baking dish.
Photo 8. In a small bowl, mix together the breadcrumbs and melted butter.
Photo 9. Sprinkle the breadcrumb mixture over the casserole. Note: if you want to make it ahead, you can cover it at this point and refrigerate until ready to bake. If you do this, be sure to add 5-10 minutes to the baking time.
Photo 10. Bake the casserole in a 350 degree oven for 20-25 minutes. Enjoy!
Expert Tips
Use a Block of Cheese - and shred yourself. It will melt so much better than pre-shredded cheese.
Undercook the Vegetables - it's okay if they're not completely cooked after 5 minutes in the microwave. They will continue cooking when they bake.
Prep Ahead - you can prep this entire dish up until the baking step and then cover and refrigerate until you're ready to bake. Add 5-10 minutes to the baking time to account for starting from a cold temperature.
Bake it Uncovered - you want the top to get nice and crispy!
Recipe FAQs
Yes. Fully prep and assemble the casserole, but don't bake it. Cool, cover, and refrigerate up to 2 days. Bake straight from cold but add 5-10 minutes.
Yes. Doing this ensures the vegetables are tender.
Other Thanksgiving Side Dish Recipes to Consider
If you make this recipe, please let me know! Leave a ⭐️⭐️⭐️⭐️⭐️ rating on this recipe below and leave a comment, or take a photo and tag me on Instagram with #greensnchocolate.
Broccoli Cauliflower Casserole
Ingredients
- 2 heads broccoli about 3-4 cups, chopped into florets
- 1 head of cauliflower chopped into small florets
- 3 tablespoon butter
- ½ white onion diced
- 3 cloves garlic minced
- 10 ounce cream of chicken soup
- ½ cup mayonnaise
- ½ cup sour cream
- ½ teaspoon salt
- 2 tablespoon milk
- 1 ½ cups shredded cheddar cheese
Crunchy Breadcrumb Topping
- 1 cup breadcrumbs I like to use the garlic herb kind
- 3 tablespoon melted butter
Instructions
- Preheat the oven to 350 degrees F.
- Grease a 9x13" baking dish with cooking spray.
- In a medium saucepan, melt the butter over medium heat.
- Add the onion and cook for 5-7 minutes, until softened.
- Add the garlic and cook one more minute.
- Place the cauliflower and broccoli in a large microwave-safe bowl and add ¼ cup of water. Cover with plastic wrap and microwave for 5 minutes to steam.
- Drain the water out of the bowl.
- In a medium bowl, mix together the cream of chicken soup, mayonnaise, sour cream, milk, and salt.
- Add the creamy mixture to the veggies and stir well to combine.
- Spread into the prepared casserole dish.
- Combine the breadcrumbs and melted butter, and sprinkle over the vegetables.
- Bake in the preheated oven for 20-25 minutes, until the casserole is bubbling and the breadcrumbs are golden.
- Serve and enjoy!
