There’s just something about the warm, cheesy, and comforting layers in this Broccoli Cauliflower Casserole Recipe that makes it a true crowd-pleaser. The tender veggies paired with a rich, creamy sauce and golden breadcrumb topping create a perfect dish for any occasion.

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

Honestly, this casserole has been a favorite in my family for years. It strikes that perfect balance of hearty vegetables and cheesy indulgence. It’s the kind of dish that comforts you inside out and makes you feel right at home, even on a busy weekday night.

Simple Prep: The ingredients are easy to find and prepping the veggies is straightforward, making it manageable for anyone.
Creamy, Cheesy Goodness: The homemade cream sauce with sharp cheddar and parmesan adds the perfect cheesy punch without being overwhelming.
Crunchy Topping: The buttery breadcrumb topping is the ideal contrast to the creamy base and tender veggies, adding just the right amount of texture.
Make-Ahead Friendly: You can prep it up to 48 hours before baking, which is great for planning meals or entertaining.

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 part of this casserole comes together beautifully thanks to the freshness of the veggies and the creamy, cheesy sauce. Choosing fresh broccoli and cauliflower ensures the casserole isn’t watery and holds its structure well after baking.

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 broccoli florets give that vibrant green color and a slight snap that stands up well to baking.
Cauliflower: Its mild flavor complements the broccoli and soaks up the creamy sauce wonderfully.
Butter: Essential for cooking the onions and garlic and adds richness to the sauce and breadcrumb topping.
Onion: Gives a sweet, savory depth and aroma once sautéed.
Garlic: Adds a subtle zesty kick that wakes up the flavor.
All-purpose flour: Helps thicken the creamy sauce into that luscious coating that clings to the veggies.
Milk: Creates the base for the sauce; adjust the amount to get perfect creaminess.
Fresh thyme: A fragrant herb that brings a lovely earthy brightness.
Salt & Black pepper: Always crucial for seasoning and balancing flavors.
Sharp cheddar cheese: The star of the show — gives sharpness and gooey melted texture.
Parmesan cheese: Adds a nutty, salty component that boosts the savory profile.
Bread crumbs: Create that irresistible crispy topping.
Garlic powder: Sprinkled into the crumbs for a little extra garlic punch.

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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

I love playing around with casseroles, and this Broccoli Cauliflower Casserole Recipe is no exception. You can easily tweak it depending on your mood or dietary needs without losing its delicious charm.

Variation: Sometimes I add cooked crispy bacon bits for an extra savory crunch—this little addition never fails to impress guests.
Dairy-Free Option: Use almond or oat milk and dairy-free cheese if you want a lighter or allergen-friendly version.
Extra Veggies: Feel free to sneak in some diced carrots or mushrooms for a fun twist.
Spicy Kick: Add a pinch of red pepper flakes to the sauce if you enjoy a bit of heat.

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

Step 1: Prepare and Precook the Veggies

To start, wash and chop your broccoli and cauliflower into roughly 1-inch pieces. I like to give them a quick boil or steam for about 4-5 minutes just until they’re semi-tender. You want them soft enough to enjoy but still holding their shape—overcooking here can lead to a mushy casserole, which nobody wants.

Step 2: Create the Creamy Sauce

Next, melt the butter in a large skillet and sauté the diced onion and minced garlic until fragrant and tender, about 4-5 minutes. It’s one of my favorite smells in the kitchen! Whisk in the flour to create a roux and cook until it thickens, then slowly whisk in the milk to get a smooth, creamy sauce. Season with salt, pepper, and fresh thyme to brighten the whole thing up. Make sure to keep whisking so no lumps form — it makes all the difference.

Step 3: Assemble the Casserole

Pour the creamy sauce evenly over your steamed broccoli and cauliflower in a lightly greased baking dish. Then sprinkle the sharp cheddar and parmesan cheese on top—you can’t go wrong with that cheesy layer.

Step 4: Make the Topping and Bake

Mix the bread crumbs, garlic powder, and melted butter in a bowl until everything is nicely coated. Sprinkle this mixture over the casserole evenly. Pop it into the oven at 350°F (175°C) and bake for 15-20 minutes until the top is beautifully golden brown and crispy and the veggies are tender when pierced with a fork.

Top Tip

After making this casserole several times, I realized the key to a perfectly creamy texture lies in the sauce prep. Whisking constantly while adding the milk prevents lumps, and adjusting milk amounts depending on your flour roux thickness helps you tailor the sauce consistency just right.

Constant Whisking: This keeps the sauce smooth and silky, no clumps allowed.
Veggie Doneness: Semi-tender veggies before baking prevent overcooking and mushiness in the final dish.
Cheese Quality: Using sharp cheddar really amps up the flavor—don’t substitute with mild if you want that punch.
Breadcrumb Ratio: Mixing breadcrumbs with melted butter helps them crisp up nicely, so don’t skip that step.

How to Serve Broccoli Cauliflower Casserole Recipe

broccoli cauliflower casserole - Serving Suggestion

Garnishes

I usually top this casserole with a sprinkle of freshly chopped parsley or chives just before serving—it adds a pop of color and freshness that contrasts beautifully with the warm, cheesy base.

Side Dishes

This casserole pairs wonderfully with simple protein mains like roasted chicken, baked salmon, or even a juicy steak. For a vegetarian meal, I like to serve it alongside quinoa or a light green salad to balance the richness.

Creative Ways to Present

For a holiday dinner, I once baked individual servings in mini ramekins topped with tiny sprigs of thyme for a fancy look. It’s fantastic for portion control and presentation when you want to impress guests without fuss.

Make Ahead and Storage

Storing Leftovers

Leftovers keep really well in an airtight container in the fridge for 3-4 days. I gently reheat them in the oven at 325°F to maintain that crispy topping rather than resorting to the microwave which can make it soggy.

Freezing

This casserole freezes perfectly. I recommend assembling it up to the breadcrumb topping, then wrapping tightly with foil and freezing. When ready, bake from frozen, adding some extra time until bubbly and golden.

Reheating

Reheat leftovers in a 350°F oven covered with foil for about 15 minutes, then uncover and bake another 5-7 minutes to crisp up the top. This keeps everything tasting fresh and delicious.

Frequently Asked Questions:

Can I use frozen broccoli and cauliflower for this casserole?

While fresh broccoli and cauliflower give you the best texture, you can use frozen. Just make sure to thaw and drain any excess water before assembling to avoid a watery casserole.

How long can I prepare this casserole ahead?

You can prepare it up to 48 hours in advance, keep it refrigerated until ready to bake, then bake it fresh before serving.

What if my sauce is too thick or too thin?

If the sauce feels too thick after adding the milk, add a splash more milk to loosen it up. If it’s too thin, let it cook a little longer to thicken before pouring over the veggies.

Can I add other cheeses or ingredients?

Absolutely! This casserole is forgiving. Feel free to mix in other cheeses like mozzarella for stretchiness or add cooked ham or bacon for extra flavor.

Final Thoughts

This Broccoli Cauliflower Casserole Recipe quickly became a go-to in my kitchen because it manages to be both comforting and fresh at the same time. It’s perfect for family dinners, holiday spreads, or even meal prepping ahead. Trust me, once you try this, it will earn a spot in your regular rotation, bringing cheesy, veggie-filled joy to your table with minimal fuss.