Cheesy Broccoli and Cauliflower Casserole Recipe
Move over au gratin potatoes: a new cheesy casserole is stealing the show. And it’s healthy! This broccoli and cauliflower casserole is as cheesy and delicious as any mac n’ cheese, except full of veggies. Our wonder blender cheese sauce packs in flavor AND nutrition with a hidden ingredient for added protein and fiber!
This cheesy broccoli and cauliflower casserole is a huge win in my book. I downed it as if it were a heaping plate of homemade mac n’ cheese without even really realizing I was eating a hefty serving of veggies! It’s seriously comforting and delicious. And nutritious!
The other win? It’s easy! Aside from the veggies taking their time to roast, the cheese sauce comes together super easily! In an earlier version of this recipe I made a roux base for the sauce, which is great and all, but it’s not the quickest or easiest technique. So I was determined to find an easier and, if possible, healthier way.
…And I did!
Healthy blender cheese sauce
Where do I start with this sauce? I love that it’s made in the blender. Seriously so easy! And I love what’s in it… cheese and a secret ingredient!
Okay, okay, here it is. The secret ingredient in this fantastic cheese sauce is… beans! Cannellini beans, to be precise. They thicken the sauce nicely and add some protein!
With protein, this dish can now serve as either a side dish or a vegetarian main. Though, I would likely add another cup of beans to bulk up the protein content if I were serving it as the main course, personally.
The how-to of this sauce is simple. Rinse and drain the beans, then put all the sauce ingredients into the blender (except a little cheese to use on top of the casserole). Blend until smooth. That’s it!
Broccoli and Cauliflower Casserole
But I got ahead of myself. Starting at the beginning, you’ll need to get your oven heated to 400* F. While it’s heating, chop your broccoli and cauliflower.
Broccoli is pretty straightforward to cut, but I have always dreaded cauliflower. I feel like it always becomes a mess and it’s tough to get past the leaves to cut properly. So I figured out a better way! If you, too, want to find a better way to cut cauliflower, here’s the post I just wrote on the easier way to cut cauliflower.
You’ll want to cut your cauliflower a little smaller than the broccoli for this recipe. Not minced or anything, but just give it a few good chops so that the pieces are small enough to come together well in casserole form.
Tossing the veggies in a tablespoon of olive oil in the casserole dish you plan to use makes for less mess and greases your pan at the same time. Sprinkle on a little salt and pepper and then slip them into the oven for 20 minutes. I recommend mixing them about halfway so that they get evenly roasted since they’re not in a single layer.
This is when you blend up your sauce, mentioned above. Mix the sauce into the veggies once they’ve roasted for 20 minutes. Then top with a bit of remaining cheese and place in the oven again. I cooked mine for about 25 more minutes, but I like my veggies pretty firm so you may want to add another five minutes or so if you like yours soft.
Try this cheesy broccoli and cauliflower casserole with your family and see how it goes! Are your kids more likely to eat cooked veggies covered in cheese sauce?
Ingredients
- 3 1/2 cup broccoli, florets
- 3 1/2 cup cauliflower, florets
- 1 tablespoon olive oil
- 1/8 teaspoon salt
- 1/8 teaspoon black pepper, ground
Sauce
- 15 ounce cannellini (white kidney) beans, canned
- 1 1/2 cup milk
- 2 cup cheddar cheese, shredded
- 1 teaspoon mustard
- 1/2 teaspoon onion powder
- 1/4 teaspoon salt
Instructions
- Preheat oven to 400* F. Chop broccoli into florets and cauliflower into more finely chopped pieces. Toss with olive oil and some salt and pepper in a 3 quart baking dish. Place in the oven for 20 minutes, stirring halfway.
- Meanwhile, rinse and drain cannellini beans.
- In a blender, combine beans, milk, 1 3/4 cups grated cheddar cheese, mustard, onion powder, and salt. Blend until well combined.
- After 20 minutes, remove broccoli and cauliflower from the oven and mix the blender sauce evenly into the veggies. Top with remaining 1/4 cup cheese.
- Place casserole back into the oven for 25-30 more minutes, until veggies are softened to liking.
Nutrition
Natalie Monson
I'm a registered dietitian, mom of 4, avid lover of food and strong promoter of healthy habits. Here you will find lots of delicious recipes full of fruits and veggies, tips for getting your kids to eat better and become intuitive eaters and lots of resources for feeding your family.
Learn More about Natalie
For kids who seem afraid of green, wouls this work with just cauliflower? Or maybe cauliflower and red bell peppers? How about freezing this –maybe before the last round of baking??
Hi Carrie! All cauliflower would work really well, I think – just use two heads. And red bell peppers sound delightful too, though I haven’t tried it. I believe this would work well frozen – if done before the last round of baking, you’ll just need to bake for longer once you take it out since it’ll be cold. Otherwise freeze after finished and reheat when needed. If you try either of these variations we’d love to hear how it goes for you!
Do you mean ground mustard or regular mustard? Thanks!
Hi Abbey, for this I just used regular yellow mustard from the bottle. Good clarification!
I tried this and it was SO tasty! Thank you!!
I’m so glad you liked it!! It’s always wonderful to hear when someone finds success with a recipe!
Would it be ok to use frozen broccoli and cauliflower instead? I normally steam cook them, never tried roasting
Should the casserole dish be covered in the oven? (new to cooking in general so this may be a dumb question…)
Thanks!
Made this today for a family potluck. Everyone loved it! I added some garlic powder, Worcestershire, and a dash of hot sauce and the flavours were perfect. (I loved the idea of using blended beans as a thickener–genius!) I used a food processor versus a blender, which I think worked out well. Many thanks!
LOVED this – the whole family loved it. We added chicken and a little garlic powder and it was amazing!
Hi. I think this recipe will be great with the sauce made with cannellini beans, but it seems to me are still high in calories for a meatless dish. More than a cheeseburger! I will make it no matter what, but I might cut down in cheese and use low fat milk…
Please tell me, are the nutrition stats found here for the entire casserole, or per serving. I don’t see how 1/4 of the dish (or one of four servings) would be 693 calories. Thanks!
Hi Jan! The nutrition stats have been fixed. Sorry about that!
Can this be made a day ahead?
Hi! Love your recipes. Wondering if this cannellini bean/milk/cheese puree could act as a general sauce? A lot of the food I make for my son can be froze – including tomato sauce and a spinach cheesy sauce. Do you think this puree could 1) Act as a general “sauce” that I could put on pasta, veggies, meat? and 2) Be froze in cubes to take out individually when needed?
Thanks so much!
So I was pretty hesitant about this because of the beans being a main component of the sauce, but I just tried it before I poured it on the veggies and wow! I really am blown away! This sauce is wonderful.. I am using frozen veggies so I will let you guys know how it turns out but woah, the sauce is fantastic!
Delicious! Love the hidden protein in the sauce. I added chicken and garlic as well, and it turned out fantastic. I have made it since and have upped the sauce quantity because we liked it with more.
Toddler wouldn’t try it but my husband and I liked it.
I’m not sure what I did, but it was watery and had a grainy texture. Definitely did not look like the picture! That being said it was still tasty and will try to make again!
It was easy to make and my son liked it. I can see adding more veggies such as peas and carrots.
Will not fix again. Gritty with the beans, nobody could eat it. We had to toss it and we aren’t picky eaters. Very disappointing.
I just had broccoli on hand. Pretty good but slightly gritty due to the beans. The family really liked it!
Made it tonight for dinner and we loved it. Roasting the veggies first gave them extra awesome flavour. Super easy to make.
My husband is finicky and even he ate it. He is not a big creamy/white sauce fan, but loved the beans pureed in there. I never thought of adding beans to sauces before. Excellent idea.
can’t find nutrition info… need it for diabetic guest … otherwise sounds like a good recipe!
Hi Nancy! We don’t calculate nutrition facts for these recipes on the site, BUT they are all calculated automatically in the connected cooking app, Prepear. Every one of our recipes is already in the app, and it’s free to use. You can sign up here: https://www.prepear.com/
Because these days we avoid going out to get a missing ingredient I,m wondering if I can use another kind of white bean (great northern or navy)?
Yes, you can definitely sub in a different kind of bean. Get creative and use what you have!
What if I use frozen cauliflower rice?
Has anyone tried this? I didn’t see anything in the comments.
We haven’t tried using cauliflower rice- it might make the consistency a bit ‘soupier’ without the larger pieces of cauliflower. It shouldn’t affect the taste, however. Good luck!