American Side Dish

Creamy Brussels Sprouts Gratin

Tender Brussels sprouts baked in a rich, garlicky cream sauce and topped with a golden, bubbling cheese crust that will win over even the pickiest eaters.

Imagine pulling a bubbling, golden-topped casserole dish out of the oven and catching that first whiff of nutty Gruyere, roasted garlic, and cream. That is exactly what this Creamy Brussels Sprouts Gratin delivers every single time. The sprouts turn perfectly tender inside the velvety bechamel sauce, and the cheesy crust on top gets beautifully browned and crispy at the edges. It is the kind of dish that turns a humble vegetable into something truly show-stopping.

This gratin is the perfect recipe to pull out for holiday gatherings, Sunday dinners, or any time you want a hearty, comforting side dish that feels a little fancy without requiring a culinary degree. It pairs wonderfully with roasted meats, a simple roast chicken, or even on its own as a satisfying vegetarian main. The creamy sauce and melted cheese do all the heavy lifting, making Brussels sprouts utterly irresistible to people who swear they do not like them.

I first made this dish on a cold November evening when I had a bag of Brussels sprouts in the fridge and absolutely no desire for anything light or simple. What came out of the oven was so creamy, so deeply savory, and so satisfying that it immediately became a recurring request at every family dinner since. If you have ever struggled to get people excited about Brussels sprouts, this recipe is about to change everything.

Recipe at a Glance

⏱Prep Time20 mins

🔥Cook Time45 mins

🕐Total Time1 hr 5 mins

🍰Servings6 servings

🇺🇸CuisineAmerican

🔢Calories~380 per serving

Ingredients

Brussels Sprouts

2 lbs fresh Brussels sprouts, trimmed and halved

1 tablespoon olive oil

1/2 teaspoon salt

1/4 teaspoon black pepper

Cream Sauce

3 tablespoons unsalted butter

4 garlic cloves, minced

1 small yellow onion, finely diced

3 tablespoons all-purpose flour

2 cups whole milk, warmed

1 cup heavy cream

1 teaspoon Dijon mustard

1/2 teaspoon freshly grated nutmeg

1 teaspoon salt

1/2 teaspoon black pepper

Cheese Topping

1 cup shredded Gruyere cheese, divided

1/2 cup freshly grated Parmesan cheese

1/2 cup panko breadcrumbs

1 tablespoon unsalted butter, melted

Substitutions & Variations

★If you cannot find Gruyere, shredded Swiss cheese or sharp white cheddar work beautifully and melt just as smoothly into the sauce.

★Swap whole milk and heavy cream for 3 cups of half-and-half if you want a slightly lighter sauce that still stays rich and creamy.

★For a gluten-free version, use a 1-to-1 gluten-free flour blend in the bechamel and replace the panko with gluten-free breadcrumbs.

★Frozen Brussels sprouts can be used in a pinch; just thaw them completely and pat them dry before roasting to avoid excess moisture in the dish.

★Add 4 strips of cooked, crumbled bacon to the cream sauce for a smoky, savory twist that takes this gratin to the next level.

Step-by-Step Instructions

1

Preheat the Oven

Preheat your oven to 400 degrees Fahrenheit and position a rack in the center. Lightly grease a 9x13-inch baking dish or a similar two-quart gratin dish with butter or cooking spray and set it aside while you prepare everything else.

2

Prep and Roast the Brussels Sprouts

Trim the bottoms off each Brussels sprout and slice them in half lengthwise. Spread them out in a single layer on a large rimmed baking sheet, drizzle with olive oil, and season with salt and pepper. Toss to coat evenly. Roast for 18 to 20 minutes, flipping halfway through, until the cut sides are lightly golden and the sprouts are just tender but not fully cooked through. They will finish cooking in the gratin.

3

Start the Bechamel Sauce

While the sprouts are roasting, melt 3 tablespoons of butter in a medium saucepan over medium heat. Add the diced onion and cook, stirring occasionally, for about 4 minutes until softened and translucent. Add the minced garlic and cook for another 60 seconds until fragrant, being careful not to let it brown.

4

Build the Roux

Sprinkle the flour over the butter, onion, and garlic mixture. Stir constantly with a wooden spoon or whisk for about 1 to 2 minutes, cooking the raw flour taste out. The mixture will look like a thick paste. This step is important for creating a sauce that thickens properly without any starchy flavor.

5

Add the Milk and Cream

Slowly pour in the warm milk about 1/2 cup at a time, whisking constantly after each addition to keep the sauce smooth and lump-free. Once all the milk is incorporated, pour in the heavy cream and continue whisking. Let the sauce cook over medium heat, stirring frequently, for about 5 to 6 minutes until it thickens enough to coat the back of a spoon.

6

Season the Sauce

Remove the pan from the heat and stir in the Dijon mustard, freshly grated nutmeg, salt, and black pepper. Taste the sauce and adjust the seasoning as needed. Stir in 3/4 cup of the shredded Gruyere until it melts completely into the sauce and everything looks smooth and glossy.

7

Combine Sprouts and Sauce

Transfer the roasted Brussels sprouts to your prepared baking dish, spreading them out in an even layer. Pour the warm cheese sauce over the sprouts, making sure everything gets well coated. Use a spatula or spoon to gently nestle the sauce down around the sprouts so it reaches all the way to the bottom of the dish.

8

Prepare the Cheese Topping

In a small bowl, combine the panko breadcrumbs, the remaining 1/4 cup of Gruyere, all of the Parmesan, and the melted tablespoon of butter. Stir everything together until the crumbs are evenly coated and the mixture looks like damp, coarse sand. This topping is what gives the gratin that irresistible golden crust.

9

Top and Bake the Gratin

Sprinkle the breadcrumb and cheese mixture evenly over the top of the gratin in a generous, even layer. Place the dish in the preheated oven and bake for 22 to 25 minutes until the sauce is bubbling around the edges and the topping is deep golden brown. If the top is browning too quickly, tent it loosely with foil after the first 15 minutes.

10

Rest and Serve

Remove the gratin from the oven and let it rest for 5 to 10 minutes before serving. This allows the creamy sauce to settle slightly so it scoops out cleanly rather than running all over the plate. Serve it directly from the baking dish with a large spoon and enjoy every golden, cheesy bite.

Pro Baker Tips

✓Warming the milk before adding it to the roux prevents lumps and helps the sauce come together much faster and more smoothly.

✓Do not skip the initial roasting step for the Brussels sprouts; it removes excess moisture and adds a subtle caramelized flavor that makes the whole dish taste deeper and more complex.

✓Shred your own Gruyere from a block rather than using pre-shredded cheese, which contains anti-caking agents that can make the sauce grainy instead of silky.

✓If you prefer a more intense cheesy flavor, swap half of the Gruyere for sharp aged cheddar or fontina cheese.

✓You can assemble the entire gratin up to 24 hours ahead of time, cover it tightly, refrigerate it, and bake it straight from the fridge, adding an extra 10 minutes to the bake time.

Storage & Serving Notes

◆Store any leftovers in an airtight container in the refrigerator for up to 4 days.

◆To reheat, cover the dish with foil and warm it in a 350-degree oven for 15 to 20 minutes until heated through, then uncover for the last 5 minutes to crisp up the topping again.

◆Microwave reheating works for individual portions; use a microwave-safe dish and heat in 60-second intervals, though the topping will lose some of its crispness.

◆This gratin does not freeze particularly well because the cream sauce can separate upon thawing, so it is best enjoyed fresh or within a few days of making it.

Serving Suggestions

This rich and creamy gratin is versatile enough to pair with a wide range of mains and occasions.

›Serve alongside a classic herb-roasted chicken for a comforting and complete Sunday dinner

›Pair with sliced roast beef or a holiday prime rib for an elegant and crowd-pleasing spread

›Spoon over a bowl of steamed white rice for a simple and satisfying vegetarian meal

›Serve as part of a Thanksgiving or Christmas dinner spread next to mashed potatoes and stuffing

›Enjoy with a crusty baguette to soak up every last drop of the creamy sauce

Frequently Asked Questions

Can I use frozen Brussels sprouts instead of fresh?

Yes, you can use frozen Brussels sprouts. Thaw them completely and pat them very dry with paper towels before roasting. Frozen sprouts contain more moisture than fresh, so drying them thoroughly is key to getting a good roast and avoiding a watery sauce.

My sauce turned out lumpy. How do I fix it?

If your bechamel has lumps, use an immersion blender or carefully transfer it to a countertop blender and blend until smooth. The most common cause of lumpy sauce is adding cold milk too quickly, so adding warm milk gradually while whisking constantly prevents this from happening in the first place.

Can I make this gratin ahead of time for a dinner party?

Absolutely. You can assemble the entire dish up to 24 hours in advance, cover it tightly with plastic wrap or foil, and refrigerate it. When you are ready to bake, remove it from the fridge about 20 minutes before it goes in the oven and add about 10 extra minutes to the bake time to account for the cold starting temperature.

What can I use instead of panko breadcrumbs for the topping?

Regular dry breadcrumbs work fine, though they produce a slightly denser crust. Crushed Ritz crackers add a buttery, salty flavor that is delicious. You can also skip the breadcrumbs entirely and just use extra cheese for a topping that is more melted and cheesy than crunchy.

Is there a way to make this dish lighter or lower in calories?

You can lighten it up by replacing the heavy cream with additional whole milk or using half-and-half instead of both milk and cream. Reducing the cheese by about a third will also cut calories without sacrificing too much flavor. The dish will be slightly less rich but still very satisfying and delicious.

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Go Make It!

This Creamy Brussels Sprouts Gratin is the kind of recipe that quietly becomes a family tradition. It is warm, comforting, deeply flavorful, and beautiful enough to sit at the center of any dinner table. Whether you are feeding a crowd on Thanksgiving or just making a weeknight meal feel a little more special, this dish always delivers. Give it a try, and do not be surprised when everyone asks you to make it again and again.