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Ultra-creamy and cheesy – this Brussels Sprouts au Gratin requires just 8 ingredients (plus a few pantry staples) and 15 minutes of hands-on preparation! Featuring roasted brussels sprouts and pearl onions smothered in a decadent, creamy gruyere cheese sauce, and topped with a buttery, crunchy topping! These restaurant-worthy gratin brussel sprouts are the perfect delicious and easy side dish for any occasion. One bite and these cheesy sprouts will become a family favorite!
“Outrageously delicious! Thank you for sharing this recipe!”
– Suzanna
Update: This recipe was originally published in November 2014. I made updates to the article below to include more information about making this brussels sprout gratin recipe at home.
Hi friends! Are you ready for the creamiest, dreamiest, most swoon-worthy side?
Today’s recipe just so happens to be my all time favorite vegetable side dish, especially for the holidays! And, after you give it a taste, I’m confident you and your family will love it too!
Table of Contents
- About this brussels sprouts gratin recipe
- What is brussels sprouts au gratin?
- Ingredients for brussels sprout gratin
- How to make brussels sprouts au gratin
- FAQs: frequently asked questions
- Serving brussels sprout au gratin
- Storing leftovers
- Recipe testimonials!
- More brussels sprout side dish recipes!
- Brussels Sprouts Gratin
About this brussels sprouts gratin recipe
This recipe for au gratin brussels features a combination of roasted tender-crisp brussels sprouts and sweet pearl onions smothered with a creamy, rich cheese sauce. Sprinkled with a crunchy, buttery topping and baked until golden brown and bubbly around the edges, this vegetable side dish is so delicious even the brussels sprouts haters will ask for seconds (or thirds)!
Listen up, especially if you think you don’t like sprouts! The brussels sprouts in this gratin are NOTHING like the memories you hold of your grandmother’s or mother’s sprouts (no offense to them). You know those over-cooked, mushy, sad and lifeless sprouts. These gratin brussels sprouts are everything a vegetable should be – they’re perfectly tender-crisp, flavorful and highly delicious!!
I pinkie promise you will love these sensational sprouts! If you plan on having a veggie hater at your holiday table, or perhaps you, yourself, are the sprout hater, well then, you simply must try this gratin recipe! Fair warning though, prepare to be totally blown away in the very best way. There is a very good chance this dish will even transform you into a brussels sprouts addict for life!
Why this recipe works
- So much flavor! Infusing the cream sauce with aromatics adds extra flavor, while the cheese and seasonings do their traditional thing.
- Perfectly tender-crisp sprouts! Partially roasting the brussels sprouts before assembling the gratin ensures they are *chef’s kiss* tender-crisp.
- Ultra rich and creamy gratin sauce! Baking the brussels au gratin uncovered allows the cream sauce to continue thickening and beautifully coat the vegetables.
- Chef tested and approved! This recipe is tried, true and easy to follow. Plus, it tastes pretty perfect, too!
Ingredients for brussels sprout gratin
This easy brussels sprout side dish is rich and bursting with flavor! This cheesy sprout recipe only requires 8 ingredients, plus a few pantry staples, to create a dish that is insanely delicious!
- Brussels Sprouts: You need 1 pound of brussels sprouts. Look for ones that are bright green in color and firm to the touch. Their leaves should be tightly packed. I recommend selecting small to medium size brussels sprouts as they are sweeter and more tender than the larger ones.
- Pearl Onions: While frozen pearl onions aren’t the most attractive vegetable, they are incredibly convenient! Make sure you fully thaw and thoroughly pat them dry. You can absolutely use fresh onions if desired – just make sure you trim, blanch and peel them before proceeding with the recipe.
- Butter: Use unsalted butter so you can control the saltiness of the dish!
- Garlic: One clove of fresh garlic adds a distinctive, punchy taste.
- Thyme: Fresh thyme infuses the sauce with a subtle earthy flavor.
- Flour: Two tablespoons of all-purpose flour help thicken the creamy sauce.
- Cream: Two cups of heavy cream creates the base for a luxurious, rich sauce. While you may be tempted to cut calories and use half & half or milk, don’t!
- Seasonings: Ground nutmeg, kosher salt and ground black pepper all provide flavor.
- Cheese: A combination of gruyere and parmesan cheese add dynamic, complex flavor. Make sure you freshly shred the cheese yourself. The pre-package shredded cheeses contain preservatives that prevent it from properly melting.
- Topping: A combination of crunchy Panko breadcrumbs and buttery pine nuts create a beautiful gratin topping!
Recipe variations
- Cheese: If you want to swap out the cheeses, you can substitute the parmesan with pecorino romano. The best substitutes for gruyere are Comté, Emmental or Jarlsberg. However, if you are looking for a completely different flavor, you can try Swiss or even cheddar cheese.
- Bacon: Crispy bacon is an obvious choice if you are looking to take this dish to the next level! Scatter some crispy, crumbled bacon on top of the vegetables before adding the cheese sauce.
- Pearl Onions: Not a fan of pearl onions? No problem! Simply omit the onions and use more brussels sprouts instead!
- Double the recipe: Need to feed a more mouths? Wonderful! You can easily double this recipe to feed a crowd!
Step by step photos: making this recipe at home
(Don’t forget to scroll down for the in-depth measurements and instructions in the complete printable recipe card at the bottom of the post!)
FAQs: frequently asked questions
You’ve got questions? I’ve got answers! If you have a question you don’t see listed below, please drop them in the comments section. I’m happy to help when I can!
What type of cheese to use in a Brussels sprouts gratin?
You can use a wide variety of cheeses for brussel sprout gratin.
While an aged sharp cheddar or semi-soft fontina can work in au gratins, the best combination for brussels sprouts is gruyere and parmesan. Gruyere has a nutty taste with a hint of sweetness and it has wonderful melting properties. And, parmesan has a natural umami flavor and grates beautifully. Together, gruyere and parmesan give the dish a well balanced, complex cheesy flavor!
What is an au gratin pan?
An au gratin pan is a cooking vessel perfectly suited for gratin dishes. Au gratin pans are wide and shallow which expose ingredients more directly to heat.
Gratin pans come in a variety of shapes and sizes from individual servings to larger portions. However, gratin pans are commonly oval and about an inch and a half deep.
What do you use an au gratin pan for?
While au gratin pans are ideal for preparing traditional, oven baked gratins, they are actually quite versatile!
You can use an au gratin pan to cook casseroles, baked pastas, vegetables, pot pies and fish. If you are preparing a dish that requires broiling the top to form a crisp crust, a gratin pan is the perfect vessel!
Can you make this Gratin brussels in advance?
This brussels sprouts recipe can easily be prepared a day ahead of time!
To make gratin brussels sprout casserole ahead of time
- Assemble and bake: Prepare and bake the casserole according to the recipe instructions.
- Cool: Allow the dish to cool to room temperature.
- Store: Cover the dish with aluminum foil and place in the refrigerator.
- Reheat: Uncover the dish and let it sit out on the counter while you preheat an oven to 350°F. Bake for 20-30 minutes, or until warm throughout.
This homemade brussels sprouts au gratin is simple to make and the perfect complement to any meal! Easy, cheesy and perfectly delicious, this is a recipe your whole family will love!
Until next time, friends, cheers – to stellar side dishes!
Cheyanne
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Recipe testimonials!
Here’s what readers are saying about this easy cheesy brussels sprouts recipe!
- “Very very good!” – Tina
- “A delicious new addition to our holiday dinners!” – Wendy
More brussels sprout side dish recipes!
If you love these cheesy sprouts, try one of these delicious recipes next:
Brussels Sprouts Gratin
Equipment
- Au Gratin Pan or 2-Quart Baking Dish
- Medium Saucepan
- Small mixing bowl
Ingredients
- 1 Pound Brussels Sprouts – trimmed, outer leaves removed & cut in half or quartered (SEE NOTE)
- 8 ounces Frozen Pearl Onions – thawed & patted dry (SEE NOTES)
- 2 TBS Olive Oil
- Kosher Salt & Ground Black Pepper – to taste
Sauce:
- 2 TBS Unsalted Butter
- 1 Clove Garlic – thinly sliced
- 2 tsp fresh Thyme Leaves – roughly chopped
- 2 TBS All Purpose Flour
- 2 Cups Heavy Cream – at room temperature (SEE NOTES)
- 1/8 tsp Ground Nutmeg
- 1 1/4 Cup Shredded Gruyere Cheese – DIVIDED (about 4 ounces)
- 1/2 Cup Shredded Parmesan Cheese – DIVIDED (about 1.7 ounces), plus more for serving
Topping:
- 2 TBS Unsalted Butter – melted & cooled
- 2/3 Cup Panko Bread Crumbs (can substitute fresh bread crumbs)
- ¼ Cup Pine Nuts – roughly chopped
Instructions
- Preheat Oven: Arrange oven rack to center position. Preheat oven to 400 degrees F. Spray a 2 quart gratin or baking dish with non-stick cooking spray. Set aside.
- Prepare the topping: In a small mixing bowl, combine the panko, pine nuts, 1/2 cup gruyere, and 1/4 cup parmesan. Season with 1/8 teaspoon of salt and a pinch of pepper. Add in the melted and cooled butter. Stir well to combine. Set aside.
- Par-bake Vegetables: Line a large, rimmed baking sheet with aluminum foil for easy clean up. Add brussels sprouts and onions. Drizzle with oil and season with 1/2 teaspoon salt and 1/4 teaspoon of pepper. Toss well to coat. Spread the vegetables out in an even layer. Bake for 15-20 minutes, tossing halfway through cooking, or until vegetables are almost fork tender. Remove from oven and transfer to prepared baking dish.
- While the vegetables are baking, Make the Sauce (SEE NOTES): In a medium-size saucepan, melt the butter over medium heat. Add the flour and stir continuously for 1-2 minutes or until the mixture is blonde in color. While whisking constantly, gradually add in the cream. Add the nutmeg and season with 1/4 teaspoon of salt and 1/8 teaspoon of pepper. Bring mixture to a gentle simmer and reduce heat as needed to maintain a gentle simmer. Cook, whisking frequently, until the sauce is thickened and coats the back of a spoon, about 5-8 minutes. Turn off the heat. Add in 3/4 cup of gruyere cheese. Whisk until smooth. Add in 1/4 cup parmesan. Whisk until the cheeses are fully incorporated. Taste and adjust for seasoning with salt and pepper.
- Assemble the gratin: Pour the sauce evenly over the brussels sprouts and onions in the prepared baking dish. Use a spatula to spread the sauce out in an even layer. Sprinkle the crunchy topping evenly over the sauce.
- Bake: Bake gratin UNCOVERED, for 20-25 minutes or until the sauce is bubbling and the top is golden brown. If the top starts to brown too quickly towards the end of baking, lightly tent the dish with aluminum foil.
- Rest and Serve: Allow to rest for 5 minutes before serving. Garnish with more parmesan and fresh thyme! Enjoy!
Video
Notes
- Brussels Sprouts: You want the brussels sprouts to be uniform in size. If the brussels sprouts are huge, quarter them. If they are on the medium or small side, half them. You want them to be roughly the same size as the onions.
- Onions: Frozen pearl onions are so much more convenient than fresh! Thaw the completely in the refrigerator overnight. Pat them thoroughly dry before proceeding with the recipe.
- Cream: To ensure your sauce is lump-free, make sure you use room temperature (or close to it) heavy cream. Remove the cream from your refrigerator and let it sit on the counter while you prep all the ingredients.
- The Creamy Sauce: Make sure you slowly whisk the cream into the roux (butter and flour mixture). Do this by adding the cream a little bit at a time, whisking until smooth between each addition. This will ensure your sauce is silky and thick!
- Want to add Bacon? You can easily add bacon if desired! Scatter cooked, crumbled bacon on top of the par-roasted brussels sprouts and onions in the baking dish. Then, pour on the cheese sauce and top with crispy topping.
Nutrition
Did you make this recipe?
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Debbie
Made this for Thanksgiving and it was a hit and so easy to make. Everyone agreed this should be a staple of our holiday dinners. A quick note regarding the make-in-advance directions: reheating the cooked gratin caused the cheese sauce to separate slightly. It was still delicious, but a bit oily. Next time I will add the sauce to the brussel sprouts, keep the topping separate, and assemble and bake the gratin on site.
Cheyanne Holzworth
Hi Debbie,
I’m honored you decided to make this recipe for brussels sprouts au gratin and absolutely thrilled you enjoyed it. Thank you so much for your note on making the recipe in advance – I do appreciate it! 🙂
Cheers and warmest wishes for a wonderful holiday season,
Cheyanne
Jeanette
I plan on making this for Thanksgiving. Is there a way to make this ahead of time to be baked the next day? I checked the notes and comments but didn’t see anything about being able to do that.
Cheyanne
Hi Jeanette,
Great question! You can definitely make this dish in advance – please see the directions included in the post here: https://www.nospoonnecessary.com/brussels-sprouts-gratin/#Can_you_make_this_au_gratin_recipe_in_advance
Please let me know if you have any other questions as I’m always happy to help! Cheers! 🙂
joe
Super delicious and met with rave reviews from my kiddos. Definitely making this again, thanks!
Cheyanne
Hi, Joe,
I’m so thrilled to hear both you and the kiddos enjoyed these brussels sprouts! Day made! Thank you so much for coming back and leaving a review. I hope you have a wonderful week!
Mary Ann | The Beach House Kitchen
I remember this gratin Chey! So perfect for the upcoming holidays! Fabulous new photos and video! I’m thinking this will definitely be on our Tgiving menu!
Matt – Total Feasts
I love a good gratin! I could easily see this being at my family’s Christmas dinner!
Kevin
Definitely an easy yet flavorful dish! I bet this Brussels sprouts au gratin will go over very well over here!
Kelsie | the itsy-bitsy kitchen
LOVE these! Brussels are my favorite so I’m adding this to the Thanksgiving menu for sure! Have a great weekend, Chey!
Mary Ann | The Beach House Kitchen
What a fantastic gratin Chey! I’m a huge fan of brussels sprouts. I’m still trying to talk Mr. Picky into them, but our oldest son Sean is finally a fan. This would be totally perfect for Tgiving! Pinned!
Kelley @ Chef Savvy
I absolutely love Brussels sprouts! I have never had them in a gratin. Now I will. Can’t wait to make this as a side dish for dinner this week. Thanks!
Cheyanne Bany
Kelley, Thank you so much for stopping by! Hope you love these creamy sprouts as much as I did!! <3
Cheryl
Girl, your words and photos are superb!!! I love Brussel sprouts and can’t wait to try this recipe!
Cheyanne Bany
Cheryl, this was absolutely amazing! I used the left overs and mixed it with some pasta and it was even good like that! Hope you try it! 🙂
Carin
Do you think this could be made in advance?
Cheyanne Bany
Hi Carin! This absolutely can be made in advance! The instructions for how to do so are in the notes portion of the recipe. Hope you give this a try and love it as much as we do!! Cheers and thank you so much for stopping by!