Brussels Sprouts Au Gratin with Parmesan Crust

Brussels Sprouts Au Gratin: Your New Favorite Comfort Food Side Dish

Hey there, friend! Chef Emily here, waving from my flour-dusted kitchen. Is there anything better than the smell of something cheesy, creamy, and utterly decadent baking in the oven? It’s the kind of aroma that pulls everyone into the kitchen, noses first, asking that magical question: “Is it ready yet?”

Today, we’re taking a humble, often misunderstood veggie—the mighty Brussels sprout—and transforming it into the star of the show. Forget everything you thought you knew about these little green gems. We’re not just roasting them (though that’s delicious too!). We’re enveloping them in a luxuriously creamy, garlic-infused cheese sauce and crowning it all with a crispy, golden, Parmesan-panko crust that crackles with every bite.

This Brussels Sprouts Au Gratin is the ultimate side dish hero. It’s sophisticated enough for your holiday table—think Thanksgiving or Christmas dinner—but easy and comforting enough for a cozy Sunday supper alongside a simple roast chicken. It’s the dish that converts sprout skeptics and has the veggie-lovers begging for seconds. So, tie on your favorite apron (the messy one with all the character!), and let’s make something incredibly delicious together.

A Holiday Kitchen Disaster That Started It All

This recipe holds a special place in my heart because it was born from a near-catastrophe! Picture this: It’s my first year hosting Friendsgiving. I’m feeling ambitious, the menu is a mile long, and my tiny kitchen looks like a hurricane blew through it. My prized green bean casserole, a family recipe, is moments away from going into the oven when… *crash*. A rogue oven mitt sends it tumbling to the floor. Creamy mushroom soup and crispy onions are now a modern art installation on my tiles.

Panic mode: ON. I had a giant bag of Brussels sprouts destined for simple roasting, but that wasn’t going to cut it now. I had to think fast. I whipped up a quick cheese sauce (a skill every cook should have in their back pocket!), tossed the par-roasted sprouts in it, and frantically searched for a topping. All I had was panko and a wedge of Parmesan. I crossed my fingers, sprinkled it on, and shoved it in the oven.

Friends, it was a MIRACLE. That desperate, thrown-together dish ended up being the absolute hit of the night. Everyone raved about it, and it’s been a permanent fixture on my holiday menu ever since. It just goes to show that some of the best recipes come from happy little kitchen accidents and a whole lot of love.

🧀 Gathering Your Au Gratin All-Stars

Here’s everything you’ll need to create this masterpiece. I’ve included some of my favorite chef-y insights and substitutions so you can make this dish your own!

• 1 ½ lbs Brussels sprouts, trimmed & halved – Look for firm, bright green sprouts that are similar in size for even cooking. Don’t be afraid of the loose outer leaves—they get deliciously crispy when roasted!
• 2 tbsp olive oil – For roasting. Its high smoke point and neutral flavor are perfect here.
• 2 tbsp butter – The rich, flavorful base of our roux. Unsalted is best so we can control the seasoning.
• 2 cloves garlic, minced – My non-negotiable addition for a flavor punch. For a milder taste, you can use 1 clove.
• 2 tbsp all-purpose flour – This is what we’ll use to thicken our sauce into luscious, gravy-like perfection.
• 1 ½ cups milk (whole or 2%) – Whole milk will give you the creamiest sauce, but 2% works beautifully too. For a richer sauce, substitute half the milk with heavy cream!
• 1 cup shredded Gruyère cheese – This is the flavor king here. It’s nutty, slightly sweet, and melts like a dream. Chef’s Sub Tip: No Gruyère? White cheddar, Fontina, or even a Swiss cheese work great.
• ½ cup grated Parmesan, divided – We’re using half in the sauce for a salty, umami kick and half in that incredible crunchy topping. Please, for the love of flavor, grate it yourself from a block! The pre-shredded stuff just doesn’t melt the same.
• ½ tsp nutmeg (freshly grated if possible!) – This is the secret weapon! It adds a warm, subtle depth that makes the cheese sauce taste even cheesier. Trust me on this one.
• Salt & black pepper to taste
• ½ cup panko breadcrumbs – The key to an ultra-crispy, non-soggy topping. Their light, flaky texture can’t be beaten. Regular breadcrumbs will work in a pinch, but panko is superior for crunch.

👩‍🍳 Let’s Get Cooking: Building Your Gratin, Step-by-Step

Don’t let the fancy name fool you—this process is straightforward and oh-so-satisfying. Follow these steps, and you’ll have a flawless gratin every single time.

Step 1: Roast Those Sprouts to Perfection
Preheat your oven to 400°F (200°C). On a large baking sheet, toss your halved Brussels sprouts with the olive oil, a good pinch of salt, and a few cracks of black pepper. Spread them out in a single layer, cut-side down. This is my #1 tip for getting those gorgeous, caramelized, crispy edges we all love! Roast for 20 minutes, until they’re tender and have some beautiful brown spots. This step is crucial because it concentrates their flavor and prevents a watery gratin.

Step 2: Create the Creamy, Dreamy Cheese Sauce
While the sprouts are roasting, let’s make the sauce. In a medium saucepan, melt the butter over medium heat. Add the minced garlic and sauté for just 30 seconds until fragrant—don’t let it burn! Sprinkle in the flour and whisk constantly for about 1 minute. This cooks out the raw flour taste and creates your roux, the thickening base of the sauce.

Now, slowly pour in the milk, whisking continuously. I mean it—don’t stop whisking! This is the secret to a smooth, lump-free sauce. Keep whisking as the mixture comes to a gentle simmer and thickens enough to coat the back of a spoon, about 3-5 minutes.

Remove the sauce from the heat. Stir in the shredded Gruyère and half of the Parmesan until the cheese is fully melted and the sauce is smooth and velvety. Stir in that pinch of nutmeg, then taste it! This is your moment. Season with salt and pepper until it tastes just right to you.

Step 3: The Big Combine
Add your beautifully roasted Brussels sprouts to the cheese sauce and gently fold them until every nook and cranny is coated in that cheesy goodness. Pour the entire mixture into a 2-quart baking dish—a pretty ceramic dish or a classic glass Pyrex works perfectly.

Step 4: The Crunchy Crown
In a small bowl, mix the panko breadcrumbs with the remaining Parmesan cheese. Sprinkle this mixture evenly over the top of the cheesy sprouts. This topping is going to bake into a glorious, golden-brown crust that provides the perfect textural contrast to the creamy interior.

Step 5: Bake Until Bubbly & Golden
Reduce your oven temperature to 375°F (190°C). Bake the gratin for 20-25 minutes, or until the sauce is bubbling vigorously around the edges and the top is a deep, golden brown. If you want an extra-crispy top, you can pop it under the broiler for the last 1-2 minutes—but watch it like a hawk!

Step 6: The Hardest Part… Wait!
I know, the smell is incredible and you just want to dive in. But let the gratin rest for about 5-10 minutes after pulling it out of the oven. This allows the sauce to set just slightly, making it easier to serve beautiful, clean scoops.

🍽️ How to Serve Your Masterpiece

This dish is the ultimate team player on any table. Here’s how I love to serve it:

The Holiday Centerpiece: This is its natural habitat. It pairs magnificently with Honey Glazed Ham, Herb-Roasted Turkey, or a standing Prime Rib Roast. It brings a vibrant, cheesy element that complements all the classic holiday flavors.

Elevated Weeknight Dinner: Who says gratins are only for holidays? Serve it as a show-stopping side next to a simple seared steak, rotisserie chicken, or pan-seared pork chops. It turns an ordinary dinner into something special.

The Vegetarian Main Event: For a meatless Monday, this gratin is hearty enough to be the main course! Serve it with a light, bright arugula salad dressed with a lemony vinaigrette to cut through the richness. Perfection!

However you serve it, make sure you get a spoonful with a bit of the creamy interior, a soft sprout, and that crunchy topping all in one bite. That’s the experience right there!

✨ Get Creative: Delicious Recipe Variations

Once you’ve mastered the classic, have fun playing with flavors! Here are a few of my favorite twists:

• Bacon Lover’s Delight: Cook 6 slices of chopped bacon until crispy. Use the bacon fat to roast your Brussels sprouts for an extra layer of smoky flavor. Fold the cooked bacon into the cheese sauce along with the sprouts, and use it as part of your topping along with the panko.
• Everything Bagel Twist: Swap out the panko-Parmesan topping for a mixture of ½ cup panko + 2 tablespoons Everything Bagel Seasoning. The sesame seeds, garlic, and onion create an insane flavor combo.
• Lightened-Up Version: You can make this a tad lighter without sacrificing creaminess! Use a lower-fat milk and a light sprinkle of cheese. For a gluten-free version, use a 1:1 gluten-free flour blend and gluten-free panko breadcrumbs.
• French Onion Inspiration: Caramelize one large onion (low and slow for about 30 minutes) and stir it into the cheese sauce. The sweet, deep flavor of the onions paired with the Gruyère is a match made in heaven.
• Spicy Kick: Add a pinch of cayenne pepper or a few dashes of hot sauce to the cheese sauce. Or, for a finishing touch, sprinkle the baked gratin with a few red pepper flakes for a little heat.

🧑‍🍳 Chef Emily’s Notes & Kitchen Stories

This recipe has evolved so much since that fateful Friendsgiving. I’ve learned that roasting the sprouts first is non-negotiable—it’s the difference between a flavorful, caramelized dish and a steamed, soggy one. The garlic was my husband’s idea (“more garlic, always!”), and he was absolutely right.

I also have a funny story about the nutmeg. I once grated a little too enthusiastically and ended up with a *very* potent sauce. My friend’s toddler took one bite, made a face, and said, “This tastes like Christmas… too much.” So, a little goes a long way, folks! But it’s now the ingredient that people can’t quite place but know they love.

The best part of this recipe is how it brings people together. It’s the dish that gets requested, the one people talk about the next day. That, to me, is the true mark of a great recipe.

❓ FAQs & Troubleshooting: Your Questions, Answered

Q: Can I make this Brussels sprouts au gratin ahead of time?
A: Absolutely! You can assemble the entire dish—right up to sprinkling the topping—cover it tightly, and refrigerate it for up to 24 hours. When you’re ready, bake it straight from the fridge. You’ll just need to add 5-10 extra minutes to the baking time since it’s starting cold.

Q: My sauce turned out grainy. What happened?
A: This usually happens if the heat is too high when you add the cheese. Too much heat can cause the cheese to seize and release its oils. Always remove the sauce from the heat before stirring in the cheese. Also, make sure you’re using freshly shredded cheese, as pre-shredded bags contain anti-caking agents that can prevent smooth melting.

Q: My gratin is too watery. How can I fix this?
A: The most common culprit is not roasting the Brussels sprouts first. Roasting draws out a lot of the inherent moisture. If you’re still concerned, you can also blanch the halved sprouts in boiling water for 2-3 minutes before roasting to help remove even more water. Finally, make sure your cheese sauce is nice and thick before you combine it with the sprouts.

Q: Can I use frozen Brussels sprouts?
A: I don’t recommend it for this specific recipe. Frozen sprouts contain a lot more water and will release it during baking, leading to a soupy gratin. Fresh is definitely the way to go for the best texture and flavor.

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🥗 A Quick Note on Nutrition

I’m all about balance! While this is definitely a indulgent, comfort food dish, Brussels sprouts are nutritional powerhouses packed with fiber, vitamins C and K, and antioxidants. The cheese provides protein and calcium. So, while it’s rich, you’re still getting a good dose of veggies!

This nutritional info is an estimate per serving (based on 6 servings):

• Calories: ~280
• Protein: 11g
• Fat: 18g
• Carbohydrates: 17g
• Fiber: 4g

Remember, enjoying food made with love and shared with others is one of the healthiest things you can do for your soul!

Final Thoughts from My Kitchen to Yours

Well, my friend, there you have it—my heart and soul in a baking dish. This Brussels Sprouts Au Gratin is more than just a recipe; it’s a reminder that the best meals often come from a place of love, a little improvisation, and the joy of sharing.

I hope this dish finds its way to your table and becomes a new tradition for you and your loved ones. I hope it converts the skeptics and delights the veggie-lovers. Most of all, I hope it makes your kitchen feel warm and your heart feel full.

If you make it (and I really hope you do!), please tag me @TastyChow on social media so I can see your beautiful creations! Nothing makes me happier than seeing you all in your kitchens, whipping up something delicious.

Until next time, happy cooking!

— Emily 🧡