Cheesy Brussels sprouts gratin is the ultimate side dish, combining the earthy, slightly nutty flavor of shredded Brussels sprouts with a rich, velvety cheese sauce. This dish is topped with a golden, crispy panko breadcrumb mixture that adds the perfect crunch to every bite. Whether you’re a Brussels sprouts lover or looking to convert a skeptic, this gratin will steal the show at any dinner table!
For more easy, cheesy side dishes perfect for family gatherings, consider making my butternut squash and Gruyere cheese gratin, this creamy, garlicky potato gratin, or this cheesy cauliflower casserole next!
What You’ll Need
- Brussels sprouts, trimmed and shaved. A food processor fitted with a slicing disc is the quickest method for slicing them. Alternatively, you can use a mandoline or a sharp knife to thinly slice the Brussels sprouts by hand.
- Béchamel (one of the French mother sauces, so creamy and delicious!): you’ll need unsalted butter, all-purpose flour, and whole milk. I like to flavor this béchamel sauce with fresh thyme, garlic, Gruyère, Parmesan, salt, pepper, and grated nutmeg. It’s absolutely packed with flavor!
- The crunchy panko breadcrumb topping is made with: panko, additional shredded Gruyère, Parmesan cheese, grated garlic, and extra virgin olive oil.
This gratin can be assembled and baked in a standard baking dish, but I love the presentation of prepping it in a large cast-iron skillet.
Ingredient Substitutions
- Gruyère Cheese: Swap Gruyère for Swiss cheese or a sharp white cheddar for a slightly different flavor profile.
- Panko Breadcrumbs: Regular breadcrumbs or crushed crackers can be used if panko isn’t available.
- Thyme: Replace fresh thyme with ½ teaspoon of dried thyme, or use fresh rosemary or sage for an earthier flavor.
- To Make Gluten-Free: Substitute the all-purpose flour with a gluten-free flour blend and use gluten-free breadcrumbs in place of panko.
- Frozen Brussels Sprouts: You can use frozen Brussels sprouts, just be sure to thaw and drain them thoroughly before shredding and adding them to the gratin. Keep in mind that they may be softer in texture compared to fresh sprouts.
Directions
- Prepare the baking dish. Preheat oven to 425°F (220°C). Grease a large cast-iron skillet with a few tablespoons of butter.
- Make béchamel. Melt butter in a saucepan over medium heat. Whisk in flour and cook until golden, about 3 minutes. Slowly add warm milk, bring to a simmer, and whisk until thickened. Reduce heat, add fresh thyme sprigs and smashed garlic cloves. Stir in grated Gruyère, Parmesan, salt, pepper, and nutmeg. Remove thyme and garlic, then set aside.
- Assemble. Place shredded Brussels sprouts in the greased skillet, then pour the béchamel sauce over and mix well.
- Prepare the panko topping. Mix panko, remaining Gruyère, Parmesan, grated garlic cloves, and olive oil in a small bowl. Spread the mixture over the Brussels sprouts.
Bake: Cover with foil and bake for 30 minutes. Remove foil and bake for 5-10 minutes until the topping is golden and bubbly.
Let it cool slightly before serving. So cheesy and delicious — enjoy!
Ari’s Best Tips!
- Use Fresh Brussels Sprouts: While you can use frozen vegetables, for the best flavor and texture, opt for fresh Brussels sprouts.
- Grate Fresh Nutmeg: Freshly grated nutmeg enhances the béchamel sauce with a subtle warmth that complements the cheese.
- Make the Sauce Ahead: The cheese sauce can be made up to 2 days in advance and stored in the refrigerator. When ready to use, gently reheat it over low heat, whisking frequently.
Store and Freeze
To make ahead: You can assemble the entire gratin a day in advance. Store it in the refrigerator, covered with foil, and bake it directly from the fridge. You may need to add 5-10 extra minutes to the baking time.
- Store: Leftovers can be stored in an airtight container in the refrigerator for up to 3 days. Reheat in the oven at 350°F for 10-15 minutes until warmed through and the topping is crisp.
- Freeze: Assemble the gratin but do not bake it. Cover it tightly with foil and freeze for up to 2 months. When ready to bake, thaw overnight in the fridge, then bake as directed.
Serving Suggestions
This cheesy gratin with shredded Brussels sprouts is an excellent side for holiday dinners or cozy family meals. Serve it alongside a Thanksgiving turkey, roast chicken, beef tenderloin, or my brined pork chops for a hearty and satisfying spread. A crisp, fresh green salad or roasted root vegetables would also pair beautifully.
If serving this as part of a larger holiday meal, consider adding the following family-style side dishes:
Creamy, rich, and decadent! An utterly impressive family-style side dish that will convert even the pickiest of eaters!
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Cheesy Brussels Sprout Gratin with Gruyère
Equipment
Ingredients
- 1 lb Brussels sprouts, trimmed and shaved, see note below
- 6 Tbsp unsalted butter, divided
- 2 Tbsp all-purpose flour
- 3 cups whole milk, warmed
- 5 sprigs of thyme, tied together with kitchen twine
- 5 cloves of garlic, peeled and smashed + 2 cloves, grated
- 1 cup Gruyère cheese, shredded, divided, see note below
- ¼ cup Parmesan, grated, divided
- 1 tsp Kosher salt
- ¼ tsp freshly ground black pepper
- ⅛ tsp ground nutmeg
- 1 cup panko breadcrumbs
- 2 Tbsp extra virgin olive oil
Instructions
- Prepare the pan. Preheat an oven to 425F. Grease a large cast-iron skillet with 1-2 Tbsp of butter.
- Make the cheese sauce. Melt 4 Tbsp unsalted butter over medium heat in a saucepan. When melted, add 2 Tbsp all-purpose flour, then whisk until the flour is a light golden brown, about 3 minutes. You don’t want the flour getting too dark. Quickly whisk in 3 cups of warm milk, then increase the heat to medium-high. Bring to a simmer, then continue to cook and whisk for another 3 minutes. Reduce the heat to low, add 5 fresh thyme sprigs and 5 smashed garlic cloves, then cook until thick, velvety, and smooth, about 5-7 minutes. Stir in ½ cup of shredded Gruyere cheese, 2 Tbsp grated Parmesan, 1 tsp Kosher salt, ¼ tsp freshly ground black pepper, and ⅛ tsp grated nutmeg until melted and smooth, about 1-2 minutes. Set aside.
- Toss with the béchamel. Add the shredded Brussels sprouts to the greased cast-iron skillet. Remove the thyme sprigs and smashed garlic cloves from the sauce, then pour the béchamel on top. Give it a really good stir.
- Make the panko topping. In a small bowl, combine 1 cup panko breadcrumbs, remaining ½ cup shredded Gruyere, 2 Tbsp grated Parmesan, 2 cloves grated garlic, and 2 Tbsp extra virgin olive oil. Stir well, then evenly distribute on top of the Brussels sprouts.
- Bake the gratin. Cover tightly with foil, then transfer to an oven and cook for 30 minutes. Remove the foil, then cook for an additional 5-10 minutes, or until the cheese is golden brown and bubbly on top. Cool slightly, then serve!
Notes
- Brussels sprouts can be thinly sliced by hand or shaved in a food processor with the thinnest shredding attachment.
- I strongly recommend buying blocks of cheese and grating or shredding yourself. Pre-shredded cheese tends to have additives that make it harder to melt.
- To make ahead: You can assemble the entire gratin a day in advance. Store it in the refrigerator, covered with foil, and bake it directly from the fridge. You may need to add 5-10 extra minutes to the baking time.
- Store: Leftovers can be stored in an airtight container in the refrigerator for up to 3 days. Reheat in the oven at 350°F for 10-15 minutes until warmed through and the topping is crisp.
- Freeze: Assemble the gratin but do not bake it. Cover it tightly with foil and freeze for up to 2 months. When ready to bake, thaw overnight in the fridge, then bake as directed.
Let us know your thoughts!