There’s something irresistibly cozy about a warm, creamy casserole bubbling fresh from the oven, and this Broccoli Cauliflower Casserole Recipe hits all the right notes. It’s the perfect way to enjoy these two classic veggies blended into a cheesy, comforting dish that feels like a hug on a plate.

The image shows a white square baking dish filled with a casserole that has a golden brown, crumbly topping layer covering creamy, white sauce-coated broccoli and cauliflower florets underneath. A black spatula with a wooden handle is lifting a portion of the casserole, showing the thick, creamy texture of the sauce and green broccoli mixed with white cauliflower below the crunchy topping. The dish is placed on a white marbled surface with a soft white cloth in the background. photo taken with an iphone --ar 2:3 --v 7

Jump to:

Why You'll Love This Recipe
Ingredients & Why They Work
Make It Your Way
Step-by-Step: How I Make Broccoli Cauliflower Casserole Recipe
Top Tip
How to Serve Broccoli Cauliflower Casserole Recipe
Make Ahead and Storage
Frequently Asked Questions:
Final Thoughts
Broccoli Cauliflower Casserole Recipe

Why You'll Love This Recipe

This Broccoli Cauliflower Casserole Recipe is one of those dishes I always come back to, whether I’m feeding a crowd or just want something hearty for dinner. It's versatile, comforting, and downright delicious — I promise you’ll be asking for seconds.

Comfort Food at Its Best: Creamy cheese sauce with tender broccoli and cauliflower creates a cozy, indulgent side dish everyone will enjoy.
Simple Ingredients: It uses things you probably already have in your kitchen, making it easy to whip up on a weeknight or for a holiday meal.
Customizable: You can tweak the cheese types, add herbs, or even toss in extras like bacon or breadcrumbs for your favorite texture.
Make-Ahead Friendly: Prep it a day or two in advance, then pop it in the oven when you’re ready — perfect for busy days.

A close-up of a fork lifting a golden brown, crispy piece of macaroni and cheese topped with small green herb leaves, showing a creamy cheesy inside with a crunchy crumb layer on top. The dish is served on a white plate with decorative edges, placed on a white marbled surface; in the background, a white baking dish filled with more of the macaroni and cheese is visible but out of focus. A sprig of fresh thyme lies on the plate beside the macaroni. Photo taken with an iphone --ar 2:3 --v 7

Ingredients & Why They Work

Each ingredient in this Broccoli Cauliflower Casserole Recipe plays a part, balancing texture and flavor to make the dish truly stand out. Fresh veggies, creamy sauce, sharp cheese, and a crunchy topping? It’s a winning combo every time.

Flat lay of fresh broccoli florets cut into 1-inch pieces, fresh cauliflower florets cut into 1-inch pieces, diced white onion, whole uncracked brown garlic bulbs alongside minced garlic cloves, a small white ceramic bowl of golden butter cubes, a small white ceramic bowl of all-purpose flour, a small white ceramic bowl of milk, fresh thyme sprigs, a small white ceramic bowl of coarse salt, a small white ceramic bowl of whole black peppercorns, shredded sharp cheddar cheese piled neatly, shredded parmesan cheese in a small mound, a small white ceramic bowl filled with plain bread crumbs, a small white ceramic bowl containing garlic powder, a small white ceramic bowl with melted butter, all arranged symmetrically and balanced on a clean white marble surface, soft natural light, photo taken with an iPhone, professional food photography style, fresh ingredients, white ceramic bowls, no bottles, no duplicates, no utensils, no packaging --ar 2:3 --v 7 --p awthu7i m7354615311229779997

Broccoli: Fresh is best to keep that vibrant green color and slight crunch after baking.
Cauliflower: Adds a subtle nuttiness and creaminess when cooked alongside broccoli.
Butter: The base for your sauce and crumb topping — adds richness and helps meld flavors.
Onion: Sauteed until soft, it adds a gentle sweetness and depth to the sauce.
Garlic: Fresh and minced, garlic gives a warm, savory kick that complements the cheese perfectly.
All Purpose Flour: Thickens the sauce so it’s creamy without being runny.
Milk: Creates that luscious, smooth texture in the sauce; whole milk works beautifully but you can use what you have.
Fresh Thyme: Brings an herbal brightness that cuts through the richness.
Salt & Black Pepper: Essential for seasoning — don’t skip!
Sharp Cheddar Cheese: Melts smoothly and adds a classic cheesy tang that’s hard to resist.
Parmesan Cheese: Adds a savory, nutty flavor and helps with the golden crust on top.
Bread Crumbs: Gives crunch and texture contrast in the crumb topping.
Garlic Powder: Boosts the garlic flavor in the topping for extra depth.

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Note: You'll find the complete list of ingredients, along with their exact measurements, in the printable recipe card at the bottom of this post.

Make It Your Way

One of my favorite things about this Broccoli Cauliflower Casserole Recipe is how easy it is to put your own spin on it. You can really play with flavors and textures — it’s a fantastic base for creativity.

Variation: I sometimes swap out sharp cheddar for smoked gouda to give it a richer, smoky vibe — definitely a crowd pleaser!
Add Protein: Toss in cooked bacon bits or shredded chicken to make it more of a main dish.
Dietary Substitutions: Use gluten-free flour and breadcrumbs to adapt this for gluten sensitivity — no one misses a thing.
Seasonal Spin: In fall, I mix in a little sage instead of thyme for a cozy flavor twist.

Step-by-Step: How I Make Broccoli Cauliflower Casserole Recipe

Step 1: Prep and Cook the Veggies Just Right

Start by washing and cutting the broccoli and cauliflower into bite-sized pieces—about 1 inch works perfectly. Steam or boil them until they’re tender but still have a little bite left, around 4 to 5 minutes. This is key because you don't want mushy veggies after baking. Drain well and arrange them in a greased 9×13 inch baking pan.

Step 2: Create the Creamy Cheese Sauce

In a large skillet, melt the butter and cook the diced onion and minced garlic until they’re soft and fragrant, about 4 to 5 minutes. Sprinkle in the flour and whisk quickly to make a smooth paste. Gradually stir in the milk, whisking constantly until you get a creamy sauce without lumps. Add salt, black pepper, and fresh thyme to season thoughtfully—it’s your flavor backbone here.

Step 3: Combine and Cheese It Up

Pour that creamy mixture evenly over the broccoli and cauliflower in your pan. Then, sprinkle on the shredded sharp cheddar and parmesan to ensure every bite is cheesy and satisfying.

Step 4: Top With a Crispy Crumb Crunch

Mix breadcrumbs with garlic powder and melted butter until crumbly and fragrant. Spread this mixture evenly on top of your casserole. This step is the magic touch that adds texture and flavor contrast once baked.

Step 5: Bake to Golden Perfection

Bake your beautiful casserole at 350°F for about 15 to 20 minutes, just until the top is golden brown and veggies are tender. Keep an eye on it toward the end—everyone loves that perfect crispy crust!

Top Tip

Over the years, I’ve learned these little tricks that really elevate the Broccoli Cauliflower Casserole Recipe and prevent common pitfalls. Trust me, they make all the difference!

Don’t Overcook Veggies: Steaming or boiling until just tender keeps the veggies from turning into mush during baking.
Whisk Sauce Carefully: Adding milk gradually while whisking prevents lumps in your creamy sauce for that silky texture.
Use Fresh Herbs: Fresh thyme boosts flavor with brightness—dried herbs don’t provide the same depth.
Crispy Topping Is Key: Don’t skimp on the bread crumb layer; it adds delightful crunch and contrast to creamy veggies.

How to Serve Broccoli Cauliflower Casserole Recipe

Broccoli Cauliflower Casserole - Serving Suggestion

Garnishes

I like to sprinkle a little chopped fresh parsley on top right before serving — it adds a pop of color and fresh flavor that brightens the whole dish. Sometimes a dusting of extra parmesan goes on top for that salty punch.

Side Dishes

This casserole makes a perfect side to roasted chicken or grilled steak. I often pair it with a fresh green salad or some crusty bread to soak up any extra sauce. It’s also fantastic alongside mashed potatoes or a simple quinoa salad for a more filling meal.

Creative Ways to Present

For holiday dinners, I’ve served this casserole in individual ramekins topped with a little extra bread crumb and cheese — it looks charming and makes plating super easy. Another fun idea is layering the broccoli and cauliflower separately for color contrast right through the dish!

Make Ahead and Storage

Storing Leftovers

I store leftovers covered tightly in the fridge for up to 3 days. When reheated, the casserole holds up well, though the topping may lose some crispness. I like to add a few fresh bread crumbs on top before reheating to revive a bit of that crunch.

Freezing

Freezing is totally doable! I recommend assembling the casserole but skipping the breadcrumb topping; freeze it tightly wrapped. When you’re ready, thaw overnight and add the crumb topping fresh. Then bake as usual for best texture.

Reheating

To reheat, I cover the casserole with foil and warm it in a 350°F oven until heated through, about 15-20 minutes. Removing the foil in the last 5 minutes helps crisp the topping up again, which is always a crowd-pleaser.

Frequently Asked Questions:

Can I use frozen broccoli and cauliflower for this casserole?

You can use frozen veggies in a pinch, but I find fresh ones give a better texture and hold up nicer during baking. Make sure to thaw and drain well to avoid extra moisture making the casserole soggy.

How can I make this casserole dairy-free?

Try substituting the butter with dairy-free margarine, the milk with unsweetened plant-based milk like almond or oat milk, and use dairy-free cheese alternatives. The sauce might be slightly different in texture but still delicious!

Can I prepare this casserole in advance?

Absolutely! You can assemble the whole casserole up to 48 hours ahead and store it covered in the fridge. Just bake it fresh when you're ready, making sure it's bubbly and heated through before serving.

What can I serve with this broccoli cauliflower casserole?

This casserole pairs wonderfully with roasted meats, simple green salads, or even hearty grains like quinoa or rice. It’s versatile enough to accompany anything from casual weeknight meals to festive holiday dinners.

Final Thoughts

This Broccoli Cauliflower Casserole Recipe feels like one of those treasured family dishes that always brings people together around the table. I love how it’s easy to make but still feels special, and how the crispy, cheesy topping makes everyone smile. Give it a try for your next meal — I’m pretty sure it’ll become a favorite of yours, too.