Brussels Sprouts Gratin with Cheddar Gruyère and Crispy Breadcrumbs

If you're looking for a delicious way to dress up Brussels sprouts for a holiday dinner, then this creamy Brussels sprouts gratin might be just what you need.

Tender Brussels sprouts are combined with garlic, shallots, rich cream, and nutty Gruyère cheese, before being topped with buttery breadcrumbs and baked until golden brown.

The result is a comforting vegetable casserole with a lovely contrast of textures. The sprouts are tender, the cheese is creamy, and the crispy topping adds a little crunch to every bite.

This is the kind of side dish that can turn even the most reluctant Brussels sprouts eater into a fan.

And while Brussels sprouts have long been a Christmas dinner staple in Ireland, this cheesy version is a little different from the traditional boiled sprouts I remember from my childhood.

It's a wonderful addition to a Thanksgiving feast, a Christmas dinner, or even a Sunday roast.

Table of Contents

What Is Brussels Sprouts Gratin?

A gratin is a baked dish with a golden, lightly browned topping, usually made with cheese, breadcrumbs, or a combination of both.

The word gratin comes from French cooking, but the idea of covering vegetables with cheese and baking them until beautifully golden has become popular in kitchens around the world.

In this recipe, Brussels sprouts are first sautéed with shallots and garlic to bring out their natural sweetness.

They're then transferred to a casserole dish, covered with cream and shredded Gruyère cheese, and finished with a layer of buttery panko breadcrumbs.

A short spell in the oven brings everything together, creating a deliciously creamy vegetable bake with a crisp, golden topping.

It's comfort food at its finest.

Why You'll Love This Brussels Sprouts Gratin

There are plenty of reasons to add this recipe to your holiday menu.

Creamy and cheesy: Heavy cream and Gruyère cheese create a rich, comforting sauce that complements the slightly earthy flavor of Brussels sprouts.

A crispy golden topping: Buttery panko breadcrumbs provide a lovely crunch that contrasts beautifully with the tender vegetables underneath.

Perfect for special occasions: This elegant vegetable side dish looks right at home on a Thanksgiving or Christmas dinner table.

A delicious alternative to boiled sprouts: If you've never been a fan of plain Brussels sprouts, adding cheese, cream, and a crunchy topping might change your mind.

Simple ingredients: There's nothing overly complicated about this recipe. A few everyday ingredients transform humble Brussels sprouts into something special.

Brussels Sprouts at Christmas in Ireland

Brussels sprouts have been part of Irish Christmas dinners for generations.

When I was growing up in Ireland, Christmas dinner wouldn't have been complete without a big pot of Brussels sprouts bubbling away on the stove.

They were usually boiled and served with a little butter, salt, and pepper. Sometimes they were cooked a bit longer than they should have been, which probably explains why so many children weren't particularly fond of them.

Thankfully, we've discovered plenty of new ways to prepare these little green vegetables.

Roasting, sautéing, and baking Brussels sprouts bring out their natural sweetness and give them a much more appealing texture.

This gratin is definitely a departure from the traditional Irish Christmas dinner, but I think it's a lovely way to give an old favorite a modern twist.

And if you're preparing a holiday meal for a crowd, it's always nice to have a vegetable dish that's just a little bit special.

Ingredients for Brussels Sprouts Gratin

You won't need a long list of ingredients to make this cheesy Brussels sprouts casserole.

Here's what you'll need and why each ingredient works so well.

Brussels Sprouts: Fresh Brussels sprouts are the key to this recipe. You'll need two pounds, trimmed and quartered. Cutting the sprouts into quarters helps them cook evenly and makes them easier to serve. Try to choose sprouts that are firm, bright green, and similar in size.

Olive Oil: A little olive oil helps the Brussels sprouts cook in the skillet without sticking. Sautéing the sprouts before baking also helps develop their flavor.

Butter: Butter adds richness to the vegetables and helps the breadcrumb topping become beautifully golden and crisp. We're using three tablespoons in total, divided between the sprouts and the topping.

Garlic and Shallots: Garlic and shallots add a lovely savory flavor without overpowering the Brussels sprouts. Shallots are slightly sweeter and milder than ordinary onions, making them particularly good in creamy vegetable dishes.

Salt and Black Pepper: A little seasoning helps bring all the flavors together. Remember that Gruyère cheese can be quite salty, so it's best to season lightly at first.

Heavy Cream: Heavy cream adds richness and moisture, helping create the creamy texture that makes this gratin so delicious. In Ireland, double cream is a suitable alternative, although it's a little richer than American heavy cream.

Gruyère Cheese: Gruyère is a wonderful melting cheese with a slightly nutty flavor.It pairs beautifully with Brussels sprouts and gives this casserole a delicious cheesy finish. If you can't find Gruyère, a good mature cheddar or Swiss cheese can be substituted. I used a Gruyère cheddar.

Panko Breadcrumbs: Panko breadcrumbs are lighter and flakier than traditional breadcrumbs. They create a particularly crisp topping, which is a lovely contrast to the creamy vegetables underneath. Mixing the breadcrumbs with melted butter before baking helps them brown evenly.

How to Make Brussels Sprouts Gratin

This recipe comes together in a few simple steps. The Brussels sprouts are partially cooked on the stovetop before being finished in the oven.

Step 1: Prepare the Oven, Casserole Dish and Sprouts

Preheat your oven to 400°F (200°C).

Lightly grease a 3-quart casserole dish with nonstick cooking spray.

Trim the ends from the Brussels sprouts, remove any damaged outer leaves, and cut them into quarters.

If some of your sprouts are particularly small, you can simply halve them.

Step 2: Sauté the Brussels Sprouts

Heat the olive oil in a large 12-inch skillet over medium heat.

Add the quartered Brussels sprouts and cook for about 5 minutes, stirring frequently.

The sprouts should begin to soften and develop a little color around their edges.

Next, add the minced garlic, shallots, salt, and black pepper.

Continue cooking for another 5 minutes, stirring regularly, until the sprouts are beginning to soften.

Add one tablespoon of butter and stir until it melts and coats the vegetables.

The Brussels sprouts don't need to be completely tender at this stage, since they'll finish cooking in the oven.

Step 3: Prepare the Breadcrumb Topping

While the sprouts are cooking, melt the remaining two tablespoons of butter in the microwave.

Place the panko breadcrumbs in a small bowl and pour the melted butter over them.

Stir gently until the breadcrumbs are evenly coated.

This simple step helps create that lovely golden crust when the gratin is baked.

Step 4: Assemble the Gratin

Transfer the sautéed Brussels sprouts to your prepared casserole dish, spreading them into an even layer.

Pour the heavy cream over the sprouts.

Sprinkle the shredded Gruyère cheese evenly over the vegetables, followed by the buttered panko breadcrumbs.

Try to distribute the topping evenly so that every serving gets a little of that delicious crunch.

Step 5: Bake Until Golden

Place the casserole dish in the preheated oven and bake for approximately 15 minutes, or until the breadcrumbs are golden brown, the cheese has melted, and the cream is bubbling gently around the edges.

Check that the Brussels sprouts are tender when pierced with a fork. If they need a little longer, continue baking, loosely covering the dish with foil if the breadcrumbs are browning too quickly.

Remove the gratin from the oven and allow it to rest for about 5 minutes before serving.

This gives the creamy sauce a little time to settle.

Serve warm and enjoy!

Tips for Making the Best Brussels Sprouts Gratin

A few simple tricks can make all the difference when preparing this comforting side dish.

Choose fresh Brussels sprouts. Fresh, firm sprouts work best because they hold their shape during cooking. Avoid sprouts with yellowing leaves or soft spots.

Cut the sprouts evenly. Quartering larger sprouts and halving smaller ones helps everything cook at approximately the same rate.

Don't skip the skillet. Sautéing the sprouts before baking helps develop their flavor and ensures they're tender by the time the breadcrumb topping turns golden.

Use freshly shredded cheese. Gruyère melts beautifully, especially when grated from a block. Pre-shredded cheeses sometimes contain anti-caking ingredients that can affect how smoothly they melt.

Keep an eye on the topping. Panko breadcrumbs can brown quickly, especially toward the end of baking. If they're becoming too dark, loosely cover the casserole with aluminum foil.

Serve while warm. This gratin is at its best when the cheese is melted, the sauce is creamy, and the breadcrumb topping is still crisp.

Variations and Substitutions

One of the lovely things about a vegetable gratin is how easily it can be adapted to suit your family's tastes.

Try a Different Cheese: Gruyère gives this dish a delicious nutty flavor, but there are plenty of alternatives. Mature Irish cheddar would be particularly good here. Its sharp flavor pairs beautifully with Brussels sprouts. Swiss cheese, Fontina, or a combination of cheddar and Parmesan are other possibilities.

Add Crispy Bacon: For an extra savory touch, sprinkle some cooked, crumbled bacon over the Brussels sprouts before adding the cheese. Bacon and Brussels sprouts are a classic combination, and the smoky flavor works beautifully with the creamy sauce.

Use Traditional Breadcrumbs: If you don't have panko breadcrumbs, ordinary dried breadcrumbs will work. The topping may be slightly denser, but it will still turn golden and delicious.

Add a Little Mustard: A teaspoon of Dijon mustard stirred into the heavy cream can add a subtle tang that complements the cheese. It's a simple way to give the gratin an extra layer of flavor.

What to Serve with Brussels Sprouts Gratin

This creamy vegetable casserole is a wonderful accompaniment to roast meats and holiday dinners.

It's especially delicious alongside roast turkey, glazed ham, roast chicken, or a traditional Sunday roast beef dinner.

For Thanksgiving, serve it with turkey, mashed potatoes, stuffing, and cranberry sauce.

At Christmas, it makes a lovely alternative to plain boiled Brussels sprouts and pairs beautifully with roast potatoes, carrots, parsnips, and all the other trimmings.

Because the gratin is quite rich, I like the idea of serving it alongside a few simpler vegetable dishes to balance the meal.

And don't forget, this is a lovely side dish for an ordinary family dinner too. There's no need to wait for a special occasion to enjoy it.

Can You Make Brussels Sprouts Gratin Ahead of Time?

Yes, you can prepare much of this dish ahead of time, which is especially helpful when you're cooking a big holiday dinner.

Sauté the Brussels sprouts with the garlic, shallots, and butter as directed.

Allow them to cool, then transfer them to the prepared casserole dish.

Cover and refrigerate for up to 24 hours.

When you're ready to bake, add the cream and shredded cheese, followed by the freshly prepared buttered breadcrumb topping.

Because the vegetables will be cold from the refrigerator, the casserole may need a little longer in the oven.

Make sure the center is piping hot and the Brussels sprouts are tender before serving.

For the crispiest topping, I recommend adding the breadcrumbs just before baking rather than preparing the entire gratin in advance.

How to Store and Reheat Leftovers

If you're lucky enough to have leftovers, Brussels sprouts gratin can be enjoyed again the following day.

Refrigerating: Allow the gratin to cool slightly before transferring it to an airtight container. Refrigerate promptly, within two hours of cooking, and store for up to 3 to 4 days. The breadcrumb topping will soften as it sits in the refrigerator, but the flavors will still be delicious.

Reheating: For the best results, reheat the gratin in an ovenproof dish at 350°F (175°C) until heated all the way through. Cover loosely with foil if the topping begins to brown too much.

You can also reheat individual portions in the microwave, although the breadcrumbs won't remain as crisp.

Can You Freeze Brussels Sprouts Gratin?

You can freeze this casserole, but I don't particularly recommend it.

Cream-based sauces sometimes separate after freezing and thawing, and the Brussels sprouts may become softer and release additional moisture.

The breadcrumb topping can also lose its lovely crisp texture.

For the best flavor and consistency, I recommend enjoying this gratin freshly baked or storing leftovers in the refrigerator for a few days.

Frequently Asked Questions

Do I Need to Boil Brussels Sprouts Before Making Gratin?

No, there's no need to boil the sprouts for this recipe. They're sautéed in a skillet with olive oil, garlic, and shallots before being transferred to the casserole dish. This method adds flavor and helps prevent the sprouts from becoming watery.

Can I Use Frozen Brussels Sprouts?

Fresh Brussels sprouts are my first choice for this recipe. Frozen sprouts tend to release more moisture as they cook, which can make the creamy sauce a little watery. If you do use frozen sprouts, thaw and drain them thoroughly before cooking. You may also need to adjust the cooking time.

What Cheese Is Best for Brussels Sprouts Gratin?

Gruyère is an excellent choice because it melts smoothly and has a lovely nutty flavor. However, mature cheddar, Swiss cheese, and Fontina are all good alternatives. For an Irish-inspired variation, try using a mature Irish cheddar.

How Do I Keep Brussels Sprouts Gratin from Becoming Watery?

Avoid boiling the Brussels sprouts before assembling the gratin. Sautéing them helps cook off some of their natural moisture while developing their flavor. Also, avoid using a casserole dish that's too small, since overcrowding can make it harder for excess moisture to evaporate.

How Do I Know When the Gratin Is Done?

The gratin is ready when the breadcrumb topping is golden brown, the cheese is melted, and the cream is bubbling around the edges. The Brussels sprouts should also be tender when pierced with a fork.

Can I Make This Recipe Without Breadcrumbs?

Absolutely! You can leave out the breadcrumbs and simply bake the Brussels sprouts with cream and cheese. The result will be a creamy, cheesy Brussels sprouts casserole without the crunchy topping. For a gluten-free version, you can use gluten-free panko breadcrumbs instead.

Recipe Card For Brussels Sprouts Gratin

Here is the printable recipe card for your kitchen files. Remember, you can choose to print the recipe with or without process images.

A Delicious Way to Enjoy Brussels Sprouts

Brussels sprouts may not be everyone's favorite vegetable, but I think this creamy, cheesy gratin is a wonderful way to give them another chance.

The combination of tender sprouts, sweet shallots, garlic, rich Gruyère cheese, and buttery golden breadcrumbs makes this a comforting side dish that's perfect for sharing.

Whether you're planning a Thanksgiving feast, preparing Christmas dinner, or simply looking for something different to serve with your Sunday roast, this Brussels sprouts gratin is well worth trying.

I hope you enjoy this delicious twist on a traditional holiday vegetable.

And if you make this recipe, I'd love to hear how it turns out. Do you prefer your Brussels sprouts simply boiled with butter, roasted until crispy, or baked in a creamy cheese sauce?

Let me know in the comments below.

Happy cooking!