Name: Cheesy Broccoli Cauliflower Casserole
Prep time: 15 min
Cook time: 30 min
Total time: 45 min
Cuisine: American
Ingredients: 3 cups broccoli florets; 3 cups cauliflower florets; 1 tablespoon olive oil; 1 small onion, diced; 2 cloves garlic, minced; 1/4 cup all-purpose flour; 2 cups milk (dairy or unsweetened non-dairy); 1 cup shredded cheddar cheese; 1/2 cup grated Parmesan cheese; 1/2 teaspoon salt; 1/4 teaspoon black pepper; 1/4 teaspoon paprika; 1/2 teaspoon Dijon mustard; 1/4 cup plain Greek yogurt (or sour cream); 1/3 cup breadcrumbs (optional, for topping); 1 tablespoon butter, melted (for topping)

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Creamy, cheesy, and loaded with wholesome vegetables, this Cheesy Broccoli Cauliflower Casserole is everything I love in a comforting side dish. It’s easy to throw together, makes a cozy addition to any holiday spread, and works just as well for a weeknight dinner. The rich, velvety cheese sauce brings it all together, and if I have leftovers, they reheat beautifully the next day.

Cheesy Broccoli Cauliflower Casserole

Ingredients

(Tip: You'll find the full list of ingredients and measurements in the recipe card below.)

3 cups broccoli florets

3 cups cauliflower florets

1 tablespoon olive oil

1 small onion, diced

2 cloves garlic, minced

¼ cup all-purpose flour

2 cups milk (dairy or unsweetened non-dairy)

1 cup shredded cheddar cheese

½ cup grated Parmesan cheese

½ teaspoon salt

¼ teaspoon black pepper

¼ teaspoon paprika

½ teaspoon Dijon mustard

¼ cup plain Greek yogurt (or sour cream)

⅓ cup breadcrumbs (optional, for topping)

1 tablespoon butter, melted (for topping)

Directions

I start by preheating the oven to 375°F (190°C) and lightly greasing a 9x13-inch baking dish.

Then, I bring a large pot of salted water to a boil. I add the broccoli and cauliflower florets, cooking them for 3–4 minutes until just tender. After draining, I set them aside.

In a large skillet over medium heat, I heat the olive oil and sauté the diced onion until it becomes translucent, about 3–4 minutes. I stir in the garlic and let it cook for another 30 seconds.

I sprinkle the flour over the onions and stir well, cooking it for about 1 minute to remove the raw flour taste. Then, I slowly whisk in the milk until the mixture is smooth.

I continue whisking until the sauce thickens, which takes around 5 minutes.

Once off the heat, I stir in the cheddar, Parmesan, salt, pepper, paprika, Dijon mustard, and Greek yogurt until everything is melted and creamy.

I gently fold the broccoli and cauliflower into the cheese sauce, making sure they’re evenly coated.

I transfer the mixture into the prepared baking dish.

If I’m using breadcrumbs, I combine them with the melted butter and sprinkle them on top for extra crunch.

I bake the casserole uncovered for 25–30 minutes, or until it’s bubbling and golden.

After baking, I let it rest for 5 minutes before serving.

Servings and timing

Servings: 6 servings

Prep Time: 15 minutes

Cook Time: 30 minutes

Total Time: 45 minutes

Calories per serving: Approximately 285 kcal

Variations

I sometimes swap the cheddar for mozzarella or a sharp white cheddar for a different flavor profile.

For a gluten-free version, I use a gluten-free flour blend and certified GF breadcrumbs (or skip the topping altogether).

I’ve added cooked quinoa or rice before for a heartier, more filling casserole.

If I want a spicier kick, I stir in a pinch of cayenne pepper or red chili flakes to the sauce.

I’ve also tried it with roasted vegetables instead of blanched, and it adds a deeper, roasted flavor.

Storage/Reheating

To store leftovers, I place the casserole in an airtight container and refrigerate it for up to 4 days. When I’m ready to reheat, I warm portions in the microwave or reheat the entire dish in the oven at 350°F (175°C) until heated through—usually about 15–20 minutes. If it looks a little dry, I splash in a tablespoon of milk before reheating to keep the sauce creamy.

FAQs

How do I make this casserole ahead of time?

I prepare everything up to the baking step, cover it tightly, and refrigerate it for up to 24 hours. When I’m ready to serve, I bake it as directed, adding a few extra minutes if needed since it’s coming from the fridge.

Can I freeze this casserole?

Yes, I’ve frozen it both before and after baking. I wrap it tightly and label it with the date. When ready to eat, I thaw it overnight in the fridge and then bake or reheat.

What can I use instead of Greek yogurt?

If I don’t have Greek yogurt, I use sour cream or plain cream cheese. Both give a nice creamy texture and tang.

Is it possible to add protein to this casserole?

Absolutely. I’ve added cooked shredded chicken or crumbled cooked sausage to the mix before baking for a complete meal.

Can I use frozen vegetables?

Yes, frozen broccoli and cauliflower work in a pinch. I make sure to thaw and drain them well before adding, or the casserole might get watery.

Conclusion

This cheesy broccoli cauliflower casserole is a comfort food staple I keep coming back to. It’s simple, satisfying, and loaded with flavor—and it’s a great way to get more veggies on the table. Whether I’m serving it for a holiday or just a cozy weeknight meal, it always delivers.

Recipe:

Cheesy Broccoli Cauliflower Casserole

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Author: Cheryl
Total Time: 45 minutes
Yield: 6 servings
Diet: Vegetarian

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Description

Creamy, cheesy, and packed with wholesome veggies, this broccoli cauliflower casserole is a comforting and versatile side dish perfect for holidays or weeknight meals.

Instructions

Preheat oven to 375°F (190°C) and lightly grease a 9x13-inch baking dish.
Bring a large pot of salted water to a boil. Add broccoli and cauliflower florets and cook for 3–4 minutes until just tender. Drain and set aside.
In a large skillet over medium heat, heat olive oil and sauté diced onion until translucent, about 3–4 minutes. Add minced garlic and cook for another 30 seconds.
Sprinkle flour over the onion mixture, stir well, and cook for 1 minute. Slowly whisk in the milk until smooth.
Whisk continuously until the sauce thickens, about 5 minutes.
Remove from heat and stir in cheddar cheese, Parmesan cheese, salt, pepper, paprika, Dijon mustard, and Greek yogurt until smooth and creamy.
Fold the broccoli and cauliflower into the cheese sauce until evenly coated.
Transfer the mixture into the prepared baking dish.
If using breadcrumbs, mix them with melted butter and sprinkle on top.
Bake uncovered for 25–30 minutes, until bubbling and golden on top.
Let the casserole rest for 5 minutes before serving.