If you have been looking for a dish that combines comfort, elegance, and a delightful twist on a classic vegetable, this Brussels Sprouts Gratin Recipe will quickly become your new go-to favorite. It takes humble Brussels sprouts and transforms them with a creamy, cheesy sauce topped with a perfectly crispy golden crust. This gratin is rich, satisfying, and bursting with fresh flavors thanks to leeks, thyme, and a hint of nutmeg, making it an irresistible side dish for any occasion. Whether you’re serving it for a holiday feast or a cozy weeknight dinner, this Brussels Sprouts Gratin Recipe offers a winning combination of texture and taste that everyone will rave about.

Ingredients You’ll Need

A collection of ingredients neatly arranged on a white marbled surface including one large white bowl filled with thinly sliced green brussels sprouts layered unevenly with some whole small dark green leaves on top; next to it, a small speckled white bowl full of shredded pale yellow cheese; a slightly larger white bowl holding fine, beige panko breadcrumbs; nearby, a white bowl with grated Parmesan cheese, light yellow and crumbly; two small wooden bowls with dried green herbs and minced light beige garlic; a clear glass measuring cup filled with white creamy liquid; a small white bowl with olive oil; a cluster of fresh whole green leeks with visible stems; and a tiny white bowl containing salt, pepper, and a reddish-brown spice. photo taken with an iphone --ar 4:5 --v 7

Each ingredient in this Brussels Sprouts Gratin Recipe plays an essential role. From the creamy cheeses that create a luscious sauce to the fresh herbs that brighten the dish, nothing is unnecessary. These simple, thoughtfully chosen ingredients come together to give you a gratin that’s rich, flavorful, and deeply comforting.

Unsalted butter, 1 tablespoon: Used to grease the baking dish, ensuring the gratin doesn’t stick and adds a touch of richness.
Extra-virgin olive oil, 5 tablespoons: Adds fruity depth and is used in both the sautéing and breadcrumb topping for a perfect golden finish.
Leeks, 3 cups thinly sliced: Provide a subtle onion-like sweetness that complements the Brussels sprouts beautifully.
Garlic cloves, 4 minced: Infuse the dish with a warm, aromatic kick without overpowering.
Brussels sprouts, 1 pound, trimmed and shredded: The star of the dish, offering a tender yet slightly crunchy base when baked.
Heavy cream, 2 cups: Creates a rich, silky sauce that binds all ingredients together.
Gruyère cheese, 1 cup grated: Melts smoothly, providing nuttiness and depth to the gratin.
Parmesan cheese, ½ cup freshly grated: Adds a sharp, salty finish used both in the sauce and in the breadcrumb topping.
Kosher salt, 1 teaspoon: Essential for enhancing all the flavors perfectly.
Freshly cracked black pepper, ¼ teaspoon: Brings a subtle heat and spice.
Minced fresh thyme, 2 teaspoons: Offers an earthy, fragrant herbal note that elevates the whole dish.
Ground nutmeg, ¼ teaspoon: Just a pinch for warm, sweet undertones balancing the creamy sauce.
Panko breadcrumbs, 1 cup: Gives the gratin its signature crisp topping that contrasts delightfully with the creamy interior.

How to Make Brussels Sprouts Gratin Recipe

Step 1: Prepare Your Oven and Baking Dish

Start by preheating your oven to 425 degrees Fahrenheit and position a rack in the center to ensure even cooking. Lightly grease a 9×13-inch baking dish with melted unsalted butter or cooking spray; this small step helps the gratin release effortlessly and adds a gentle buttery note to the crust’s edges.

Step 2: Sauté Leeks and Garlic

Heat 2 tablespoons of extra-virgin olive oil in a large skillet over medium heat until shimmering. Add the thinly sliced leeks and cook, stirring frequently, until softened and tender—about 4 minutes. Then, stir in the minced garlic and cook just until fragrant, about one minute. These fragrant aromatics build the foundational flavor of the gratin and add a lovely sweetness that balances the Brussels sprouts’ earthiness.

Step 3: Combine Brussels Sprouts and Aromatics

Transfer the cooked leeks and garlic into a large mixing bowl. Add the shredded Brussels sprouts and toss everything together. Getting them well mixed in this step helps distribute those flavors evenly and readies the vegetables for their cheesy blanket.

Step 4: Make the Creamy Cheese Sauce

Return the skillet to the stove and pour in the heavy cream along with the Gruyère cheese, a quarter cup of the parmesan, kosher salt, black pepper, fresh thyme, and nutmeg. Stir constantly over medium heat until the cheese melts and the sauce thickens to a velvety consistency, about 3 minutes. This sauce is the heart of your Brussels Sprouts Gratin Recipe, bringing all the ingredients together in rich harmony.

Step 5: Assemble and Bake the Gratin

Pour the luscious cheese sauce over the Brussels sprouts and leeks, tossing gently to coat every shred in creamy goodness. Transfer the entire mixture into your prepared baking dish, spreading it evenly. Pop it into the oven and bake for about 20 minutes or until the Brussels sprouts are tender and everything is bubbling with anticipation.

Step 6: Prepare the Crispy Topping

While the gratin bakes, mix the panko breadcrumbs with the remaining parmesan and 3 tablespoons of olive oil in a small bowl. This topping will add that coveted golden crunch that transforms this dish from delightful to unforgettable.

Step 7: Add Topping and Finish Baking

Remove the gratin from the oven and evenly sprinkle the panko mixture on top. Return it to the oven for another 5 to 6 minutes until the crust turns beautifully golden brown and crispy. This final step adds a wonderful textural contrast to your Brussels Sprouts Gratin Recipe.

Step 8: Serve Family-Style and Enjoy!

This gratin is best enjoyed fresh and warm straight out of the oven. Gather your loved ones, grab a big spoon, and dive into this creamy, crispy celebration of Brussels sprouts.

How to Serve Brussels Sprouts Gratin Recipe

The dish shows a black cast iron pan filled with a textured casserole that has two clear layers: a thick bottom layer of light green shredded vegetables mixed with melted cheese, and a top layer of golden-brown crispy breadcrumbs with small green herb sprigs scattered on top. A wooden spoon is scooping out a portion from the pan, revealing the soft, moist inside layer under the crunchy top. The pan is placed on a white marbled surface, with a small white bowl holding a serving of the casserole visible beside it. Photo taken with an iphone --ar 4:5 --v 7

Garnishes

To enhance your Brussels Sprouts Gratin Recipe even more, consider sprinkling freshly chopped parsley or a few extra thyme leaves on top before serving. A light zesting of lemon zest can also brighten each bite with a subtle citrus kick that plays beautifully against the creamy sauce.

Side Dishes

This gratin pairs perfectly with roasted meats like chicken or pork, adding richness that balances savory mains. You can also serve it alongside a crisp green salad with a tangy vinaigrette to offset the cheesy creaminess and add refreshing crunch.

Creative Ways to Present

For a special occasion, try serving this Brussels Sprouts Gratin Recipe in individual ramekins for a charming, personal touch. Alternatively, spoon it into hollowed-out bell peppers or scoop portions onto toasted rustic bread for an elegant appetizer or brunch option.

Make Ahead and Storage

Storing Leftovers

Allow the gratin to cool completely before transferring leftovers to an airtight container. Refrigerate for up to 3 days, making it easy to enjoy a comforting, quick side any time you want without starting from scratch.

Freezing

You can freeze this Brussels Sprouts Gratin Recipe if you want to prep ahead. After baking, cool it entirely, wrap tightly with foil or plastic wrap, and place in a freezer-safe container for up to 2 months. Thaw overnight in the fridge before reheating.

Reheating

Reheat leftovers in a 350-degree oven until warmed through and the topping regains some crispness, about 20 minutes. If using a microwave, cover the dish to prevent drying out, but note the topping won’t stay as crunchy. Reheating gently preserves all the rich textures and flavors that make this gratin so special.

FAQs

Can I use frozen Brussels sprouts for this recipe?

While fresh Brussels sprouts are ideal for their texture and flavor, you can use thawed frozen Brussels sprouts in a pinch. Just be sure to drain any excess moisture well to avoid a soggy gratin.

What cheese can I substitute for Gruyère?

If Gruyère isn’t available, Emmental, mozzarella, or even a sharp white cheddar can work nicely to maintain that creamy, melty texture with a slightly different flavor profile.

Is it possible to make this recipe dairy-free?

To make a dairy-free version, swap heavy cream for coconut cream and use a vegan cheese alternative. Keep in mind this will change the flavor and texture but can still result in a delicious gratin.

Can I prepare this gratin ahead of time before baking?

Absolutely! Assemble the gratin up to the point of baking, cover well, and refrigerate for up to 24 hours. Bake when ready, adding a few extra minutes if needed to ensure it’s heated through and bubbly.

How do I get the topping extra crispy?

Using Panko breadcrumbs helps achieve incredible crunch. For even crispier topping, sprinkle in a bit more olive oil or butter, or broil for 1-2 minutes after baking—watch closely to avoid burning.

Final Thoughts

This Brussels Sprouts Gratin Recipe is a shining example of how a simple vegetable can be transformed into something truly spectacular. Its warm, cheesy, and crisp elements blend together for a crowd-pleasing side that feels both luxurious and comforting. I encourage you to try this recipe soon—you might just find yourself making it over and over for every special meal or cozy night in. Once you taste this gratin, Brussels sprouts will never be the same again!