Creamy Brussels Sprouts Gratin (Over-the-Top Cheesy)

This Creamy Brussels Sprouts Gratin is baked in a garlic gruyere cheese sauce and it’s absolute heaven. This may be my new favorite side dish!

Brussels Sprouts Gratin

Y’all, I have a new favorite side dish and I’m so excited to share this recipe! This Creamy Brussels Sprouts Gratin with garlic and gruyere is all sorts of magical and you need it in your life. You just do. It’s that simple.

Brussels sprouts are one of those foods that I used to hate when I was a kid, and I know I’m not the only one.

To be quite honest with you, I downright love them now.

Why You’ll Love Brussels Sprouts Gratin

Not even gonna say it’s the Brussels sprouts…. it’s ALL in the cheese sauce. Oh. My. Word.  It is Phenomenal. 

It’s made with Gruyere cheese which is one of the meltiest cheeses you’re going to find. It’s creamy, a little sweet/nutty, and slightly salty. The cheese sauce also has caramelized shallots and garlic.

The Brussels sprouts are quickly blanched first before baking them the rest of the way in the beyond decadent cheese sauce, which allows them to cook fully in the gratin.

A word of caution – it’s basically guaranteed that you are gonna be reaching in and pulling out crispy little edges of Brussels sprouts and cheese before it ever makes it to the table.

Oh, it’s extraordinary. And surprisingly simple!

Brussels Sprouts Gratin Ingredients

• Brussels Sprouts: When blanched and baked, they turn tender and soak up all that creamy cheese sauce.
• Shallots: Thinly sliced and sautéed, they add a mild, sweet flavor.
• Garlic: Just a little bit goes a long way to make the whole thing delicious.
• Butter: You’ll use butter to make a smooth, creamy sauce.
• Flour: This is for thickening up the sauce, helping to make a lovely cream sauce that covers every bite.
• Chicken Broth: Adds flavor and keeps the sauce from being too heavy. It blends right in to make the perfect base for your cheesy gratin. You can use store-bought broth or even homemade chicken stock.
• Milk: Whole milk makes the sauce creamy without weighing it down too much. It makes your creamy cheese sauce just right!
• Gruyère Cheese: Oh, how we love gruyere cheese! It melts beautifully and has a rich, nutty flavor that makes this gratin a crowd pleaser. It’s what gives this dish that cheesy crust on top, which turns golden brown and bubbly in the oven.
• Salt & Pepper: Just enough to bring out all those flavors.

How to Make Brussels Sprouts Gratin

1. Get the oven ready: Preheat your oven to 400°F to bake this perfect side dish.
2. Blanch the brussels sprouts: Bring a large saucepan filled with salted water to a boil over medium-high heat. Drop in the fresh brussels sprouts and let them cook for about 3 to 7 minutes until they’re just tender (depending on how big they are). Once they’re done, drain them in a colander and rinse under cold water so they stop cooking.
3. Sauté the shallots and garlic: Melt some butter in a large skillet over medium heat. Add the thinly sliced shallots and cook until they’re nice and tender. Then, add the minced garlic and cook for another 2-3 minutes.
4. Make the creamy sauce: Add the rest of thebutter to the skillet. Once it melts, whisk in the flour to make a smooth roux. Slowly add in the chicken broth and then the milk, whisking the whole time. Keep stirring until the sauce gets thick and smooth. Add half of the gruyère cheese, plus a salt and a bit of pepper to taste.
5. Combine everything: Add the blanched Brussels sprouts to the cream mixture in the skillet and stir until everything is well coated. If your skillet is oven-safe, you can leave it all in there. If not, transfer the mixture to a casserole dish.
6. Top with cheese and bake: Sprinkle the remaining gruyère cheese on top to make it extra cheesy. Pop the dish into the oven and bake for about 30 minutes, until it’s golden brown and bubbling around the edges.
7. Broil for a little extra browning: If you like that extra crispy top, turn on the broiler for a couple of minutes at the end. Just keep an eye on it, so it doesn’t burn.
8. Let it rest before serving: Take it out of the oven and let it sit for about 2-3 minutes before serving.

Tips for Making Brussels Sprouts Gratin

1. Blanching is key: Make sure you don’t skip blanching the fresh brussels sprouts. It helps them cook evenly and keeps that lovely green color. Just don’t overdo it—3 to 7 minutes should be just right.
2. Use an Oven Safe Skillet: Cooking everything in one medium saucepan or large skillet that can be transferred to the oven makes this dish easy and cuts down on dirty dishes. I always use my cast iron skillet!
3. Broil for that perfect crust: After baking, turn on the broiler for a minute or two to get that cheese golden and crispy. Watch it closely, so it doesn’t burn.

Recipe Variations

1. Add crispy bacon: For extra flavor, sprinkle some crispy bacon bits over the top before serving. It pairs so well with the cheesy brussels.
2. Try a blend of cheeses: While gruyere cheese is amazing, you can also mix in some Parmesan cheese or even swiss cheese for a slightly different taste. It’ll make your gratin even cheesier and delicious.
3. Use fresh thyme: Adding a sprinkle of fresh thyme to the sauce can give your gratin a touch of earthy flavor.
4. Use bread crumbs for a crispy top: If you like a little crunch, sprinkle some bread crumbs mixed with a bit of melted butter on top before baking. It adds a lovely, crisp topping to your brussels sprouts au gratin.

What to Serve with Brussels Sprouts Gratin

• Crockpot Chicken and Gravy
• Savory Pork Chops
• Mississippi Pot Roast
• Easy Meatloaf Recipe
• Herb Roasted Turkey

How to Store Leftovers

Let the gratin cool completely before you store it. Then, transfer the leftovers to an airtight container. Pop it in the fridge, and it’ll stay good for about 3-4 days.

If you’re planning to keep it longer, you can freeze it. Just make sure to wrap it tightly or store it in a freezer-safe container, and it should last for up to 2 months.

Reheating

1. Reheat in the oven for the best texture: Preheat your oven to 350°F. Place the leftover gratin in a shallow baking dish and cover it with foil. This helps keep the cheese from drying out. Bake for about 15-20 minutes, or until it’s warmed through. If you want that crispy top, remove the foil for the last 5 minutes.
2. Reheat from frozen: If you’ve frozen your leftovers, let them thaw overnight in the fridge. Then, follow the oven reheating steps. You can also reheat straight from frozen in the oven; just add a little extra time (about 10-15 minutes).

More Brussels Sprouts Recipes to Love

• Roasted Brussels Sprouts with Balsamic
• Parmesan Crusted Brussels Sprouts

Print Pin

Creamy Brussels Sprouts Gratin with Garlic and Gruyere

Ingredients

• 2 pounds brussels sprouts
• 3 large shallots, trimmed and thinly sliced
• 4-6 cloves garlic, minced
• 4 tbsp butter, divided
• 1/4 cup flour
• 3/4 cup chicken broth
• 1½ cups milk
• 8 ounces gruyere cheese shredded
• salt & pepper to taste

Instructions

• Preheat the oven to 400 degrees.
• Bring a large saucepan filled with salted water to a boil over medium-high heat and blanch the Brussels sprouts until just tender - about 3 to 7 minutes (it depends on the freshness and the size of the sprouts).
• Drain Brussels sprouts in a colander. Rinse gently under cold water to stop the cooking.
• Melt 2 tablespoons of the butter in a large skillet (I like to use my cast iron so I can use the same pan for the stovetop as I do for the oven). Saute the shallots until tender, then add the minced garlic. Cook for an additional 30-60 seconds.
• Add the remaining 2 tablespoons of butter. Once it melts, whisk in the flour to make a roux. Slowly add in the chicken broth followed by the milk, while whisking, until thickened and smooth. Add half of the gruyere cheese and season with salt and pepper to taste.
• Add the Brussels sprouts to the sauce and stir to combine. If using a cast iron skillet or an ovensafe pan, just leave it in the pan. If you are not, then transfer the mixture to a 2 quart casserole dish. Sprinkle with the remaining gruyere cheese.
• Bake at 400 degrees for about 30 minutes. It should be golden brown and bubbly. I like to crank up my heat to broil and broil it for a couple minutes just for a little more browning. Let this sit for 10 minutes before serving.