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If roasted garlic brussels sprouts did not change your mind about brussels sprouts, then hopefully this roasted brussels sprouts gratin with garlic crumble and crispy onion topping will.

Brussels sprouts are legit one of my favorite vegetables of all time. We have roasted brussels sprouts as least once a week and it’s always on my shopping list. I feel like those that despise them are just scarred from having a bad experience (re: boiled). You’ve gotta give this one a shot. The topping itself is WORTH IT.
Will you just LOOK at that gorgeous topping? Breaking into it was a little heartbreaking because it was like shattering the sugar top of creme brulee — but it also meant one step closer to having this delicious gratin on my plate.
I had extra garlic parmesan paste from my extra garlicky and cheesy bread so I mixed that with panko breadcrumbs to make the topping for this brussels sprouts gratin. But I didn’t stop there. I then used gourmet (as TJ’s would call it) fried onions and elevated the dish even more.
GAH YOU GUYS! You just seriously have to make this. Even if it’s not for Thanksgiving; what about for like a party or potluck? Or what if you just want pure comfort food in the form of brussels sprouts and garlicky oniony goodness? Because that’s my favorite kind of party. Well, sort of. Add some form of bubbly and friends…I’m all over that sign up list!
I wasn’t expecting this dish to be that awesome but since it is, I think this is THE dish I am bringing to Thanksgiving dinner this year! To be honest, this doesn’t have to be a Thanksgiving side dish. This can be a side dish year-round because WHY NOT?! I know Thanksgiving is pretty much all about side dishes but why not make side dishes a year-round thing?
I’m tempted to throw a side dish only party in July.
Roasted Brussels Sprouts Gratin with Garlic Crumble and Fried Onion Topping
Equipment
Ingredients
- 2 pounds (907 g) brussels sprouts, sliced in half
For the bechamel sauce:
- 4 tablespoons (56 g) unsalted butter
- 3 tablespoons all-purpose flour
- 1 ⅔ cup (394 ml) whole milk, room temperature
- Salt and pepper, to taste
- Pinch ground nutmeg
For the garlic crumble and crispy onion topping
- 3 cloves of garlic, minced
- 3 tablespoons grated parmesan cheese
- 1 cup (60 g) panko breadcrumbs
- ¼ cup (59 ml) olive oil
- 1 cup (236 g) or more, definitely more crispy onions
Instructions
- Preheat oven to 400 °F (204 °C) and place brussels sprouts onto a nonstick baking sheet. Drizzle olive oil all over then season with salt.2 pounds (907 g) brussels sprouts
- Roast for 20 minutes. Remove then set aside. Turn down the oven to 375 °F (191 °C)
- Have on hand a 2 or 3 quart casserole dish.
- While the brussels sprouts are roasting, begin making your bechamel sauce.
- In a deep skillet, melt butter over medium heat then add flour, stirring and whisking until smooth.4 tablespoons (56 g) unsalted butter, 3 tablespoons all-purpose flour
- Carefully add the milk and continue whisking until thickened, about 2-3 minutes.1 2/3 cup (394 ml) whole milk
- Season with salt and pepper and pinch of ground nutmeg.Pinch ground nutmeg, Salt and pepper
- Remove from heat then add the roasted brussels sprouts to the skillet. Toss to cover brussels sprouts in the sauce.
- Pour the brussels sprouts into the casserole dish and smooth into an even layer.
- In a small bowl, mix together the garlic, parmesan, panko breadcrumbs, and olive oil.3 cloves of garlic, 3 tablespoons grated parmesan cheese, 1/4 cup (59 ml) olive oil, 1 cup (60 g) panko breadcrumbs
- Using your hands, evenly sprinkle the topping all over the top of the brussels sprouts.
- Bake for 25 minutes or until the top is browned.
- Remove from oven and sprinkle crispy onions on top.1 cup (236 g) or more
- Let cool for 10-15 minutes before serving.
Very tasty! We enjoyed it with Thanksgiving sides as a nice change from green bean casserole.
Loved this so much! To make a quicker version I’m going to use store-bought bechamel sauce next time.
So glad you enjoyed this!
Any chance if subing the milk for coconut milk? Seems like a fairly easy recipe to “veganize”
You could, but it may curdle and the coconut milk might yield a different taste.
Are these the Durkee crispy onions that people usually put on green bean casserole? Sounds great! Thanks?
Yes, they’re the same kind of crispy onions!
Looks great. One question though – I see panko on the list of ingredients but don’t see it used in the recipe. Do you add it to the parm and garlic or to the fried onions? Thanks!!
So sorry about that! Thanks for catching it. I added it in the steps. You mix it with the parm and garlic!
Thank you!! Planning to make this on Thursday!
This amazing! I am so bringing this to Thanksgiving. Do you think this be prepped ahead of time (thru step 11??) and then popped in the oven prior to eating? Or any suggestions? Thank you. Love your blog and cookbook!
I would actually prep through steps 9. I wouldn’t mix together the breadcrumb mixture until the morning of/day of because you don’t want the panko to get soggy. I know it’ll still go in the oven to crisp up but I have a feeling it won’t crisp up as much if it’s like soaked in the olive oil.
Thank you!
Ooooooh baby, come to Momma!! This recipe looks and sounds so dang delicious! You’ve combined two of my favorite Thanksgiving side dishes, brussels sprouts and gratin! I love it!
Thanks! I hope you make it!
This looks amazing!!!
Thank you!! You must try it!
Definitely making this. Mouth is watering. Omg.
Yaasss!!!
This is making my mouth water! I need to make this this week…just because :)
I just bought some “fancy” fried jalapenos last night and I just might try adding some of those to the topping.
Omg, that would be SO good!!!