Broccoli Cauliflower Brussels Sprout Gratin

This lusciously cheesy Broccoli Cauliflower Brussels Sprout Gratin isn’t your average casserole. Ditch the canned cream-of-craziness, grab some veggies, and meet me in the kitchen!

Broccoli Cauliflower Brussels Sprout Gratin

I hope y’all are hungry because I packed an entire crisper drawer’s worth of veggies into this cheesy little holiday casserole and it. is. awesome!!!

Since my friend’s blogs all seem to have the festive treats game well taken care of, I’m happily stepping away from the baking bonanza this holiday season in lieu of my typical veggie shenanigans. Less time developing cookie recipes (which let’s face it, you already have a zillion of) means I get to spend more time making seasonal produce look so good you’ll want to lick your screen.

Challenge accepted.

Broccoli Cauliflower Brussels Sprout Gratin

Broccoli Cauliflower Brussels Sprout Gratin.

So. Much. YES!

In a nutshell? Tender broccoli, cauliflower, and brussels sprouts are blanketed with a creamy béchamel sauce with caramelized onions, Gouda, and Gruyere cheeses, then topped with crispy golden breadcrumbs for a side dish that’s destined to impress!

There are over 2 POUNDS of veggies in this tasty holiday side and, after that first bite you’ll be so glad there are! That’s the best part of a gratin-style casserole, isn’t it? Topping fresh veggies with a luscious cheese sauce that turns every indulgent bite into a swoon-worthy moment.

Ready to fall in love with your veggies?

This lusciously epic Winter Veggie Gratin isn't your average casserole. Ditch the canned cream-of-craziness, grab some veggies, and meet me in the kitchen!
4.91 from 10 votes

Broccoli Cauliflower Brussels Sprout Gratin

This lusciously cheesy Broccoli Cauliflower Brussels Sprout Gratin isn’t your average casserole. Ditch the canned cream-of-craziness, grab some veggies, and meet me in the kitchen!

Course Side Dish
Cuisine American
Keyword Broccoli Cauliflower Brussels Sprout Gratin
Prep Time 10 minutes
Cook Time 30 minutes
Total Time 40 minutes
Servings 8 servings
Calories 321 kcal
Author Jenn Laughlin – Peas and Crayons


  • 1 lb cauliflower florets
  • 8 oz broccoli
  • 8 oz brussels sprouts (quartered)
  • 2 cups onion (white or yellow)
  • 1 tsp olive oil or butter
  • 1/4 cup butter
  • 1/4 cup flour
  • 1/2 cup heavy cream (room temperature)
  • 1 cup milk (room temperature)
  • 4 oz freshly grated gruyere cheese
  • 4 oz freshly grated gouda cheese
  • 1/4 tsp salt
  • black pepper to taste
  • 1/4-1/2 cup Italian-seasoned breadcrumbs
  • 1-2 TBSP butter


  1. Pre-heat oven to 350 degrees F.
  2. Chop your veggies.
  3. Bring a pot of water to boil and blanch broccoli, cauliflower, and brussels sprouts until the broccoli turns vibrantly green and all three veggies are somewhere between al-dente and fork-tender. This will take a few minutes, but no longer than 8. When your perfect texture is reached, shock the veggies in an ice bath (more info here) to halt the cooking process. No mushy veggies here! Alternatively if you’d prefer softer veggies, feel free to let them cook a smidge longer and/or skip the ice bath.
  4. Place veggies in a casserole dish and set aside.
  5. Drizzle a medium pot (one deep enough to make your cheese sauce in) with a little bit of olive oil or butter and caramelize your onions, stirring occasionally. Continue cooking until onions are golden brown and tender.
  6. Turn your burner to medium-low heat and add 1/4 cup (4 TBSP) butter.
  7. Once your butter has melted, slowly mix in flour a tablespoon at a time, whisking the mixture together as you go.
  8. Once your roux has begun to form a paste with the onions, add room temperature (or slightly warmed) milk and cream, whisking constantly until the sauce thickens.
  9. Remove your pot from heat (it will begin to thicken even further at this part) and slowly add 1/2 the cheese.
  10. Right about now you’ll want to dive in face first with a crusty baguette. I’ll look the other way if you do, but try to save the sauce for the veggies, will ya!?
  11. Pour sauce over veggies, then top with the cheese you set aside earlier.
  12. Next melt 1 TBSP of butter in a small skillet and add breadcrumbs. Mix constantly while toasting, then sprinkle over casserole.
  13. Bake on center rack at 350 for 20 mins.
  14. Prepare to swoon.

Recipe Notes

This recipe feeds a small army, making it the perfect side dish for a family gatherings or potluck parties with friends or co-workers.

Keeping thing small scale? Don’t fret! For a smaller serving, the recipe is easily halved.

Nutrition Facts below are estimated using an online recipe nutrition calculator. Adjust as needed and enjoy!

Nutrition Facts
Broccoli Cauliflower Brussels Sprout Gratin
Amount Per Serving
Calories 321 Calories from Fat 207
% Daily Value*
Fat 23g35%
Saturated Fat 14g88%
Cholesterol 73mg24%
Sodium 404mg18%
Potassium 520mg15%
Carbohydrates 19g6%
Fiber 4g17%
Sugar 6g7%
Protein 13g26%
Vitamin A 1110IU22%
Vitamin C 80mg97%
Calcium 345mg35%
Iron 1mg6%
* Percent Daily Values are based on a 2000 calorie diet.
Broccoli Cauliflower Brussels Sprout Gratin

veggie gratin swaps + substitutions

If your cheese stash is limited, feel free to use all Gouda or all Gruyere. I love the recipe with a little of both but it will still rock with just one or the other.

No cream handy? No problem! You can use all milk. I’ve used both whole milk and 2% and they both work great!

Crazy for breadcrumb toppings? Feel free to double the recipe! As for the veggies, I’d love you to eat broccoli, cauliflower, AND brussels sprouts but if there’s a super picky eater in the bunch you can make it with just broccoli and cauli or simply a metric ton of cauliflower.

I’m pretty insistent that this recipe could make a cruciferous veggie superfan out of any hot-blooded cheese-loving individual though, so give it a try – will ya!?

so . . . how was it!?

Fantastic! We’ve had this veg-tastic side dish twice already and ADORE it! Long story short, this easy cheesy Broccoli Cauliflower Brussels Sprout Gratin is positively divine; I hope you get a chance to try it and warm up a chilly night with a big plate of comfort food!vanill

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Recipe Rating


  • Gail Silversides

    It was very good but very watery in bottom of casserole. Followed recipe but maybe roast veggies next time.

    • Hi Gail! Roasted veggies would be marvelous here and so flavorful! The veggies should not have been watery, so I’m happy to help troubleshoot if you would like. How long did you blanch them for? Any ingredient tweaks or swaps within the sauce or low fat dairy used in place of whole/full?

  • Lisa

    Looking forward to trying this? Can this be made a day ahead?

    • So excited for you to try it, Lisa! You’ll make this recipe through step 11. Save the breadcrumb topping for just before baking the next day. I usually let the casserole sit on the counter for 30-60 min before baking to take the chill off, this way I don’t need to add extra bake time and risk over-baking the sauce.

  • Andrea Grantham

    Hi there: I am trying to clean out my fridge. Can I just use cheddar?

    • Hi Andrea! Cheddar doesn’t melt quite as well and is flavored a little different but honestly I would still devour it because I adore all things cheese haha! It will have more of a nacho cheese sauce vibe to it, kind of like having broccoli with cheddar cheese sauce on it? If you’re a fan of that (I so am!) then you should be golden. xoxo

  • george basden

    How much is a serving size?

    • Hi George! Since we’re working with about 10 cups of veggies here, a serving will be about 1 + 1/4 cups of veggie goodness. You can also divide the casserole into 8 equal portions if it’s easier. xo

  • Kathryn Mainor

    What size casserole dish did you use?

    • Hi Kathryn! I went to dig mine out to measure it and I can’t find that dish anywhere right now, eek! I’d say a 9×13 casserole dish would be great and a slightly smaller one may work great as well!

  • Cathy Crowley

    Question. Do I chop the onions fine? Or slices. Making for thanksgiving. Thanks

    • Hey Cathy! Yup chop them fine – anywhere between a fine dice or mince works great!

  • Peter Griffin

    This will make me fart for days. Can’t wait to try it!

  • Gerard Buckley

    5 stars
    I was looking for a vegetable recipe that wasn’t asparagus and found this gem. We made it a few weeks ago with a roast beef as a dry run for Christmas and it was a smashing hit! We will be doing it again on Christmas. Thank you!

    PS even had the veggies as leftovers for lunch the next two days and they were still great!

    • YAYYY! Thank you Gerard! I’m so thrilled you enjoyed the recipe and that it earned repeat status. Love it so!

  • Carrie

    I’m making this now. Curious as to why the milk? You have cream and cheese and butter. Pointless to try and make this lower in fat, haha. Is it to thin out the sauce? In that case do less flour? Maybe you just wanted a lot of sauce and thought all that cream would be too much. At this point I don’t think it can get less fattening if you tried. Milk is twice the cream. I’m gonna half and half it but wanted your opinion.

    • Hi Carrie! Hoookayyyyy so I made this recipe up to be one of those totally luxe, luscious, cheesy types of gratins (I had a MAJOR craving for something both veggie-packed and indulgent) — I just got home with my kiddo and saw this question so I’m not sure if it’s too late to weigh in with some tips for lightening it up? So for the flour and butter situation, I like to keep those in equal portions to make a good thick roux for the sauce. The dairy can for sure be tinkered with as far as the cream goes and I think milk or half and half are both great swaps. I think I’m going to try it with full milk when I make it for the holidays now that you’ve mentioned it! Let me know what you ended up doing and how it went!! xoxoxo

  • Sue

    5 stars
    Jenn, you have the BEST recipes!
    I’m going to make this for Thanksgiving.
    Thank you so much!

  • bev

    Looks amazing going to make it for Thanksgiving as my veggie dish to bring.

  • Michele

    Question. Could you roast the veggies first, rather than blanch them? If so, for how long?

    • Skip blanching entirely (since it’s only an alternate cooking method) and just roast them to perfection! Love this idea Michele! I’d roast at 400 degrees F for approx. 30 minutes or to your desired level of tenderness.

  • Pat Fletchet

    I don’t see the vanilla others are referring to in the ingredient list?

    • Hi Pat! I’ve started making the recipe without vanilla and I wound up removing it from the original recipe b/c I didn’t want to scare anyone off who may be looking for a conventional veggie gratin.

  • Tayler Ross

    5 stars
    Such a delicious way to prepare so many veggies! I love it!

  • April

    5 stars
    I love this recipe! I’m always looking for new ways to eat brussels sprouts. I think my kids might enjoy them more if they tried them this way, too. Yum!

  • Casey

    5 stars
    We love this! We eat it for holidays instead of potatoes. We also live far away from any good grocery stores. Our one store doesn’t sell gruyere and we have to go to Jackson Hole to stock up. So when I don’t have gruyere (which tastes like Swiss and Parmesan had a delicious cheese baby) I grate half Parmesan and half Swiss and it tastes pretty close. My Mom’s town grocery store sells gruyere for over $10 for 2 oz.

    • It totally DOES taste like swiss and parm cheese babied it up omg! Cracking up over here! Thank you Casey! Hope you’re having a wonderful holiday weekend!

  • Annie

    5 stars
    Have you ever tried freezing this dish before step 12? I made two batches and am hoping to spread it out to another week 🙂

    • Hey Annie! I haven’t but it may work! I think if anything the veggies will be softer than usual but for the sake of food science I say try it 😉 If anything you can always add some broth to it once you thaw it back out and turn it into cheesy broccoli cauliflower veggie soup, lol!

  • Mook

    5 stars
    I was a little sceptical about the vanilla. But wow that’s a great addition.
    Instead of boiling the veggies I baked in the oven at 350 till I got a little pot of a char. It turned out fantastic!!!!

    • Ohmygosh I love that you used roasted veggies; how fantastic! Thank you so much and I’m so thrilled you enjoyed it! 🙂

  • Amelia

    This looks amazing! I’ve been searching for a new winter veggie side dish! Can’t wait to try! My local grocery store does not carry gruyere cheese, what would be the best substitute??

    • I’m so excited you’ll be trying it Amelia! You can use extra gouda in place of the gruyere (I’d stick with regular, not smoked) or use Havarti cheese (it’s super creamy!). Lots of tasty options!

  • lindsay

    Hi Jenn, thoughts on making any part of this in advance?

    • Jenn

      Hey Lindsay! Go for it! I would cook the veggies until al dente since they’ll soften a bit more as they soak up some of the sauce in the fridge. Make everything but the bread crumbs (toss ’em together before serving) and you should be good to go! Hope you adore it as much as we do!

  • Jenn this looks SO good. I make a brussels sprout gratin this time of the year that’s really tasty. I’m intrigued about the use of vanilla here!

  • Ok, I gotta tell you, I am not crazy about Brussels sprouts, but when you add the cauliflower, broccoli and cheese…i’m on board!

  • Oh my goodness, this looks and sounds mind-blowingly delicious!!

  • I’m not a fan of Brussels sprouts but I’d probably eat them in this! Yum!

  • Hahah so glad there is no canned cream of craziness as you called it here! A nice home made veggie gratin : ))

  • 5 stars
    You know I love this. Anything packed with veggies and cheese makes my heart go pitty patter.

  • Jenn, this looks like the perfect comfort side dish!

  • This is so crazy epic! LOVE it!

  • As if I needed another reason to love you – you totally stole my heart with this one! I’m always trying to (subtly, lol!) forcefeed my family veggies this time of year, but this dish would sell itself. No one would be able to resist this!!!

  • You cannot go wrong with all that cheese! Truly epic!

  • 5 stars
    This sounds incredible!!!

  • I love the addition of brussels sprouts! My dad is big on them all year but not many people seem to like them. But with a dish like this, I am sure I could win a lot of people over!

    • Jenn

      Thanks Kacey! It’s definitely a great way to introduce someone to brussels sprouts – all the veggies bring out the best in each other! The super creamy cheese sauce doesn’t hurt either! 😉

  • The vanilla in here is pure genius!

    • Jenn

      Thank you Dorothy!

  • 4 stars
    Amazing. Lifetime veggie here and that sounds different and delicious. Pinned and now following. Ty x

    • Jenn

      Thanks Katie! Happy to have you following along – welcome to Peas and Crayons! 🙂

  • Most of the time I get far more excited about veggie recipes than desserts. This is one of those times. This looks absolutely AMAZING! And I know my family will love this!

    • Jenn

      Thanks Michelle! I’m totally with you on the veggie excitement – I love how vibrant and flavorful they are!

  • Holy cow! This definitely is EPIC! I need to try it – for the cheese and for the vanilla!

    • Jenn

      You totally need this 🙂 Thanks Anna!

  • Adding vanilla extract to this gratin is a genius idea!! I can’t wait to try it.

    • Jenn

      Thanks Jenny! <3

  • Putting vanilla in a veggie gratin is somewhere between genius and crazy and I LOVE YOU FOR IT! Want.

    • Jenn

      Love you too kiddo! It’s so perfect with the caramelized onion béchamel, it was kismet! 😉

      • Jen

        I don’t see anywhere where the recipe calls for vanilla??? Do I add it?

        • Hey Jen! I originally had vanilla in the recipe to make vanilla-spiked caramelized onions and was scared it was freaking people out a bit so I removed it. No need to add any! 🙂 Hope you have a marvelous holiday weekend!

  • Epic is right – this looks amazing Jenn!

    • Jenn

      Thanks Sharon! <3

  • Hi Jen! I just found you on the net and am so glad I did! I love this post. I’m a vegetarian and it can’t get any more delicious than this for me! I am so hungry right now! 🙂 (pinned btw)

    • Jenn

      Hi Rakhee! I’m so glad you found me! Thank you and welcome to Peas and Crayons! 🙂

  • I don’t know what’s more stunning! the photos, this recipe or all that CHEESE!!!!!

    • Jenn

      Thanks Cheryl!!! Hope you get a chance to break out the cheese (and veggies – duh!) and try it <3

  • This is absolutely my favorite recipe I found today! Those beautiful green brussels sprouts!! They are calling my name! I love veggies so very much and this beautiful dish needs to happen. Thanks for sharing! Pinning!

    • Jenn

      You’re so sweet – thank you Sara! Brussels sprouts have never had it so good! 🙂

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