If you, or someone you care about, hasn’t yet converted to the sprouts side, let me introduce you to Brussels Sprouts Au Gratin. Smooth, nutty gruyere and sharp white cheddar are the perfect duo to mellow out the intense flavor of the Brussels sprouts. Whip up this impressive side dish for special occasions like Thanksgiving or Christmas for the ultimate crowd pleaser!
Glazed maple bacon Brussels sprouts may sound like a side dish straight out of Portlandia, but I assure you they’re (a) very real, (b) very delicious, and yeah, (c) a little bit extra. But, in my defense, with Brussels sprouts recipes, sometimes you need to be extra if you want a clean plate! (see also Christmas Brussels sprouts with bacon, cranberries, and pistachios).
Now, if you don’t need a lot of extra flavor, crispy shaved Brussels sprouts are a perfect shredded Brussels sprouts recipe to highlight what a change in texture can do. They’re simply seasoned but super crispy – the added surface area is a game changer both when it comes to cook time and eat-ability.
For the rest of you, don’t worry, plenty of shredded Brussels sprouts recipes don’t skimp on extra flavors. Take this shaved Brussels sprout salad with bacon, blue cheese and apple or savory breakfast Brussels sprouts hash (also with bacon). Because if there’s one thing that makes everything better, even Brussels sprouts, it’s bacon. Well, there is one other thing…
Just ask creamy cauliflower au gratin what a little cheese sauce did to boost its street cred as a Thanksgiving side dish.
I know that most Thanksgiving recipes call for maple pecan figs and balsamic cranberries, but Brussels sprouts au gratin is gonna be your new go-to. Cause there will be no extras once you’ve dredged thinly shaved Brussels sprouts in cheesy bechamel sauce and baked ’til it’s bubbly.
How to Make Brussels Sprouts au Gratin
Brussels sprouts au gratin may be enough of a “labor of love” that you save them as a Thanksgiving side. But they’re so delicious you may not be able to wait. Make a rich and creamy bechamel sauce with gruyere and cheddar, then pour over thinly shaved Brussels sprouts and bake until golden.
- Make the bechemel sauce. Melt four tablespoons of butter in a small saucepan over medium heat, then whisk in four tablespoons of flour. It will be very thick and clumpy at first.
- Pour in the milk while whisking constantly – it will gradually thin out, but you’ll need to really work the whisk to smooth out any clumps. Simmer for 5 minutes, until the sauce thickens and coats the back of a spoon.
- Add salt, pepper, and nutmeg and whisk until smooth.
- Reduce the heat to low, then start adding the cheeses in small batches. Whisk until very smooth after each addition of cheese.
- Taste the sauce for seasoning and adjust the salt and pepper to taste. Cover the pot to keep the cheese sauce warm and set aside.
- Turn off burner, remove pot from heat, cover, and set aside.
- Melt the remaining butter in a large 12″ ovenproof skillet. Add the shredded Brussels sprouts and saute until the sprouts are soft, but still bright green.
- Add minced shallots and garlic and saute 2 minutes more, stirring nearly constantly.
- Pour the bechemel sauce over the Brussels sprouts and toss until evenly combined.
- Stir the breadcrumbs with melted butter until evenly moistened, then sprinkle the breadcrumb mixture over the Brussels sprouts.
- Transfer to a 375°F oven and bake for 25 minutes, until the sauce is bubbling and the topping is golden brown.
- Serve hot or warm, and enjoy!
Recipe Notes and Tips
- For convenience and efficiency, purchase pre-shredded Brussels sprouts. These are typically located in the produce aisle in most grocery stores. You’ll need 1.5 pounds, or about 12 cups.
- If you prefer to shred your own Brussels sprouts, shred by hand using a mandoline slicer or in a food processor.
- The 1:1 mixture of flour and butter used to start the cheese sauce is called a roux. Don’t worry! The roux will will start off thick and clumpy before adding the milk, and even while mixing it in at first, but it will thin out as you continue to add more milk. Just remember – whisk, whisk, and whisk again until smooth!
- DO shred your own cheese from fresh blocks of gruyere and sharp cheddar cheeses. Pre-shredded cheeses are often coated with cornstarch and don’t melt as smoothly.
- A 12″ cast iron skillet (either enameled as shown in the photos or seasoned) is a great option for going from stovetop to oven. If you don’t have access to an oven-proof skillet, transfer the sautéed Brussels sprouts mixture to a 9×13″ casserole dish.
- A bit of freshly grated nutmeg over the top of the baked casserole really makes a huge difference!
Make It Ahead!
While you shouldn’t make Brussels sprouts au gratin ahead of time, you can prep a few components in advance:
- Shred the Brussels sprouts (if you bought them whole) and refrigerate in a sealed ziploc bag for no more than 2 days.
- Grate the cheese in advance and store in a ziploc bag. Remove as much air as possible before refrigerating. The shredded cheeses will keep well for 3-4 days.
- Make the bechamel sauce ahead of time, then store in an air-tight container in the fridge. Reheat over medium low heat, adding up to ¼ cup of milk until the sauce is smooth and has the consistency to easily pour off a spoon.
More Extra Special Thanksgiving Sides
- Sweet and Savory Twice Baked Sweet Potatoes
- Crab Mac and Cheese
- Sausage and Apple Stuffing
- Roasted Butternut Squash with Bacon and Pecans
- Kale and Brussels Sprouts Salad with Hazelnut Vinaigrette
Did you make this Brussels sprouts au gratin recipe? I’d love to know how it turned out! Leave a comment and a rating below.
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- 2-quart Saucepan
- cheese grater
- 6 tbsp unsalted butter, divided
- 4 tbsp flour
- 2 c whole milk
- 1 tsp kosher salt
- ½ tsp ground pepper
- ¼ tsp nutmeg
- 1 c shredded gruyere cheese
- 1 c shredded sharp white cheddar cheese
- 1.5 lb shredded Brussels sprouts, about 12 cups
- 2 medium shallots, thinly sliced
- 2 cloves garlic, minced
- ½ c panko breadcrumbs
- 1 tbsp melted butter
- Heat the oven to 375°F with a rack positioned in the center.
- Place a 2-quart saucepan over medium heat; add four tablespoons butter and heat until it melts, then foams. Sprinkle the flour over the butter, then work the flour into the butter. The mixture will be very thick and clumpy.
- Gradually pour in the milk while whisking constantly. It will clump at first, then thin out. Maintain the heat and bring the mixture to a steady simmer; cook until the sauce is slightly thickened and easily coats the spoon, about 5 minutes.
- Whisk in the salt, pepper and nutmeg. Reduce the heat to low, then add the cheeses in small batches (about ½ cup), whisking after each addition until very smooth. Turn off the burner, remove the pot from heat, cover, and set aside.
- Heat a 12” ovenproof skillet over medium high heat; add the remaining 2 tablespoons of butter and heat until the butter melts, then foams.
- Add the Brussels sprouts to the skillet along with a pinch of salt and toss to coat in the fat. Saute, stirring occasionally, for 5 minutes, until the Brussels sprouts start to soften and the volume decreases by at least a third. Add the shallots and garlic and saute, stirring frequently, for 2 minutes more.
- If the bechamel sauce has started to clump, return to medium low heat and whisk quickly until smooth and pourable. Pour the sauce over the Brussels sprouts and stir until the skillet contents are well combined.
- Combine the breadcrumbs and melted butter in a small bowl and mix until the breadcrumbs are evenly moistened. Sprinkle the mixture evenly over the gratin.
- Transfer to the oven and bake uncovered for 25 minutes, until the sauce is bubbling around the edges and the topping is golden brown. Flip the oven to broil for 2-3 minutes to further crisp the topping, if desired.
- Rest five minutes, then garnish with parsley and freshly grated nutmeg (if available). Serve hot or warm.