Name: Brussel Sprouts au Gratin
Prep time: 10 min
Cook time: 35 min
Total time: 45 min
Cuisine: American
Ingredients: 16oz brussel sprouts; 1 1/2 teaspoons kosher salt, divided; 1/8 teaspoon ground black pepper; 1 tablespoon olive oil; 2 tablespoons butter; 1/4 cup sweet yellow onion, minced; 1 teaspoon garlic, minced; 2 1/2 tablespoons all-purpose OR gluten-free flour; 3/4 Nutpods Original (unsweetened/unflavored) creamer OR half-and-half; 1/4 cup chicken broth (more if needed to thin); 2 tablespoons parmesan cheese, grated; 1 cup gruyere cheese, grated

Published on 04/01/23

by Erin Jensen

Our Brussel Sprouts au Gratin recipe is mouthwatering, cheesy, and so simple to put together. Enjoy tender brussels sprouts, sweet onion, and gooey cheese in every bite. Follow our simple step-by-step instructions on how to get this tasty side dish on your next holiday table.

Brussels sprouts au gratin in a casserole dish.

Simple and Savory Brussels Sprouts Au Gratin

Not that you needed convincing, but this recipe is proof that any dish with copious amounts of cheese will be a crowd pleaser. Mild flavored brussels sprouts pair perfectly with rich and tangy parmesan and creamy and nutty gruyere cheese. We especially love serving it for Easter, Thanksgiving and Christmas!

Love cheesy sides?

Then definitely check out our Cheesy Scalloped Potatoes, Delicata Squash au Gratin, or Goat Cheese Potatoes au Gratin.

What Is Au Gratin

Au gratin simply means that a dish is sprinkled with either cheese, breadcrumbs, or both and then is browned to create a crisply baked top. Potatoes Au Gratin is a classic dish that we absolutely love, and inspired this fun brussels sprouts version. Serve with our favorite Beef Tenderloin recipe or our classic baked ham!

What You Will Need

brussels sprouts – A cruciferous vegetable that has a similar flavor to broccoli and becomes slightly sweet after cooking.
kosher salt & ground black pepper – Just a bit to enhance flavors throughout.
olive oil – Used to keep the brussels sprouts from drying out during the cooking process.
butter – The perfect ingredient to bring out the best flavors in the garlic and onion.
yellow onion – A subtly sweet and sharp flavor.
garlic – Adds a subtly sharp buttery and peppery flavor.
all-purpose flour – Feel free to substitute for gluten-free flour.
Nutpods Original Creamer – Be sure to select the unflavored variety. Or use half-and-half if dairy isn’t a concern.
chicken broth – Used to thin out the creamy sauce.
parmesan cheese – A slightly fruity and nutty cheese, perfect for an au gratin dish.
gruyere cheese – Rich, creamy, and salt, this cheese has it all.

How To Cook Brussels Sprouts Au Gratin

While your oven is preheating to 400°F, prep the brussels sprouts by trimming off the stem and peeling off 2-3 layers of the leaves. Using a sharp knife and a cutting board, quarter the brussels sprouts and place them in a casserole dish.

Drizzle them with olive oil and massage it into the brussels sprouts, making sure that it coats every inch. This ensures that they don’t dry out during the cooking process. Sprinkle with salt and black pepper and place in the oven for 20 minutes, tossing half way through.

Peeled and quartered brussels sprouts in a casserole dish drizzled with olive oil and salt and pepper.

While the brussels sprouts are cooking, bring a cast iron skillet to medium-high heat and add in the butter, letting it melt to coat the bottom of the skillet. Next, add in the minced garlic and yellow onion. Move everything around the skillet for 1-2 minutes or until they become soft and fragrant.

A cast iron skillet with butter, minced onion, and minced garlic. The same skillet with the butter melted and flour added.

To create the roux, add the flour and use a whisk to combine it with the butter to create a paste. Continue whisking while adding the creamer and then the broth, approximately a quarter cup at a time. Continue whisking until the consistency is thick and creamy. If it feels too thick, add another splash or two of the broth and stir.

A whisk mixing in flour to the onion, butter, and garlic mixture.

Remove the roux from the heat and add in the shredded parmesan and half a cup of the gruyere. Stir the cheese mixture until it has all melted, take a taste, and adjust the salt and pepper as needed.

Pro Tip

We get that pre-shredded cheese is super convenient, but it also contains additives to keep it from clumping, which in turn, decreases its gooey-ness level once cooked. For the ultimate melty cheese, take the extra effort to shred your own using a cheese grater or the grater attachment on a food processor.

Roux with gruyere cheese being whisked in.

Remove the brussels sprouts from the oven and check to see that they have slightly browned on the outside and are tender on the inside.

Roasted brussels sprouts in a casserole dish.

Now pour your cheesy sauce over the top of the cooked brussels sprouts.

Cheese mixture poured over the top of the roasted brussels sprouts.

Sprinkle the remaining gruyere cheese over the cheese sauce coated sprouts and place the casserole dish back onto the middle rack of the oven for 8-10 minutes to ensure that they cheese melts all the way through.

Remaining guryere cheese sprinkled on top of the cheese mixture.

Finally, move the casserole dish to the broiler for 1-3 minutes to get that nice slightly browned top layer. The broiler still works even with the oven door slightly open so that you can keep an eye on the browning process.

Fully cooked and broiled brussels sprouts au gratin in a casserole dish.

Remove the au gratin brussel sprouts from the oven and let cool for 10 minutes before serving.

A close up of a corner of the brussels sprouts au gratin.

What To Serve With Brussels Sprouts Au Gratin

This easy side dish is here to elevate any main course. Some of our favorites are smoked ham, grilled steak, or our ultimate smoked turkey. And since it’s the season for loading up the table with our favorite sides, be sure to check out our favorite Thanksgiving side dishes for more menu inspriation.

A spoonful of brussels sprouts au gratin pulling away from the casserole dish.

Recipe FAQs and Tips:

Dairy-Free: make this recipe dairy-free by using Nutpods in place of traditional creamer.
Make now, bake later: Feel free to make the roasted brussels sprouts ahead of time and keep in the refrigerator over night. Let them come to room temperature before adding the cheese sauce and the remaining recipe steps.
Storage: Put leftovers in an airtight container and store them in the refrigerator for up to three days.

Pinterest image showing the brussels sprouts au gratin and the recipe title.

Made this yummy side dish and loved it?! We would love it if you would take a minute and leave a star rating and review – it is also helpful if you made any substitutions or changes to the recipe to share that as well. THANK YOU!

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