Melty, cheesy delicious
Have you ever been asked to bring a dish over for the holidays or another special occasion and you want to make it look like you really pulled out all the stops? Or maybe you just have a deep appreciation for vegetables disguised as vessels for cheese. In either case, this Brussels Sprouts au Gratin with Pancetta and Walnuts will fit the bill nicely.
These Brussels sprouts are tossed in garlic oil before taking a quick turn in the oven to roast until lightly crisp, then drenched in a creamy sauce and 3 types of cheese (yes, 3!) and popped back in the oven to tenderize into a melty pool of cheesy deliciousness. After a final turn in the oven, they're finished with a mix of pancetta, thyme, and toasted walnuts. The resulting dish is both creamy and rich with layers of texture to spare.
What makes Brussels Sprouts au Gratin so creamy and rich
This Brussels Sprouts au Gratin is extra creamy thanks to a simple blend of half & half, Dijon mustard, and egg which work to emulsify and bind everything together into a rich sauce that thickens as it cooks. The sauce is seasoned with a simple mix of sea salt, cracked pepper, red pepper, thyme, and a pinch of nutmeg and then topped with a blend of gruyere, white cheddar, and parmesan to become the ultimate creamy + cheesy indulgence.
2 ways to toast the nuts
Toasting nuts is a simple way to intensify flavors and improve their crunchy texture. These are my 2 favorite ways to toast them:
- Stovetop - This is my preferred way to toast small batches of nuts, like the amount used in this dish. Simply heat nuts in a dry skillet over medium heat, stirring frequently as they begin to brown and intensify in smell. Once toasted, remove the nuts from the pan so that they do not continue to cook. The whole process should take about 5 minutes.
- Oven - This is my preferred way to toast larger batches of nuts, but you can also do small batches this way if you prefer. Cover a baking sheet with parchment paper, then top with dry nuts. I like to toast at a lower temperature, usually 300 degrees F (150 C) for around 25 minutes, but you can bump this as high as 350 degrees F (180 C) for a shorter amount of time (usually around 15 minutes) if you're balancing other dishes in the oven at the same time.
For both methods, keep in mind that nuts can go from a lovely golden brown to burnt very quickly, so you'll want to keep a close eye on them as they cook. You can feel free to add herbs or spices as you cook the nuts, but oil is not necessary as the nuts will produce their own as they cook.
My favorite nut choice for this Brussels Sprouts au Gratin is walnuts, which I toast with a small amount of additional thyme. If you don't have walnuts on hand, almonds, pecans, and hazelnuts are all lovely alternatives.
Storage and reheating
These Brussels Sprouts au Gratin with Pancetta and Walnuts can be stored in an airtight container for up to 3-4 days. You can reheat in an oven-safe dish at 350 degrees F (180 C) until hot (If you find that your nuts are in danger of over-toasting you can cover the dish in foil when baking). For smaller portions, reheat in a microwave-safe dish for 3 minutes, stir, and heat at additional 30-minute intervals as needed.
Do you have to use a cast iron pan?
No, but its my favorite option for this Brussels Sprouts au Gratin recipe because it crisps the Brussels sprouts beautifully. If you do not have a cast-iron pan, you can use a large oven-safe casserole dish instead.
Tools needed to make this recipe
- a cutting board
- a chef's knife
- a large cast-iron pan or large oven-safe casserole dish
- a medium saute pan
- a spatula or wooden spoon
- a whisk
- measuring cups and measuring spoons
- a medium prep bowl
- a small dish to reserve pancetta then walnuts in
- a cheese grater (unless you buy pre-shredded cheese)
Are you looking for an upgrade to your kitchen tools or looking to replenish your pantry? Check out my kitchen tools shop page and my pantry staples shop page to find my must-have kitchen tools, pantry items, and other Whip & Wander favorites.
A note for special diets
This Brussels Sprouts au Gratin with Pancetta and Walnuts is grain-free, gluten-free, low-carb, and friendly for Keto diets.
This dish can also be really friendly for those following a low-lactose diet. The Gruyère, sharp white cheddar, and parmesan all generally contain less than 0.5g lactose per serving of cheese. For the half & half, this option is lactose-free and found at Whole Foods.
Brussels Sprouts au Gratin with Pancetta and Walnuts
- Prep Time: 10 minutes
- Cook Time: 40
- Total Time: 50 minutes
- Yield: 10 servings 1x
- Category: Sides
- Method: Oven + Stovetop
- Cuisine: French
- Diet: Gluten Free
Brussels Sprouts au Gratin with Pancetta and Walnuts is a rich and creamy holiday side dish with layers of texture to spare.
- 2 lbs Brussels sprouts, trimmed and sliced in half
- 2 tbsp garlic oil (may sub 2 tbsp olive oil + 2 cloves minced garlic)
- ½ cup half & half (I like this lactose-free version)
- 1 large egg
- 1 tbsp Dijon mustard
- 1 ½ tsp dried thyme, divided
- ¾ tsp sea salt
- ½ tsp cracked black pepper
- ¼ tsp ground nutmeg
- ¼ tsp red pepper flakes
- 1 cup Gruyère cheese, shredded
- 1 cup sharp white cheddar cheese, shredded
- ½ cup parmesan, shredded
- 8 oz pancetta, diced
- 1 cup walnuts, roughly chopped
- Preheat oven to 400 degrees F (204 C).
- In a large cast-iron pan, toss the halved Brussels sprouts with garlic oil. Roast for 15-20 minutes, or until the brussels begin to brown lightly on top, then remove from oven.
- While the Brussels sprouts roast, cook the pancetta. Set a saute pan over medium heat then add the pancetta, stirring occasionally until crisp; about 4-6 minutes. With a slotted spoon to drain the excess fat, transfer pancetta to a side dish.
- In a medium prep bowl, whisk together the half & half, egg, Dijon mustard, 1 teaspoon of the divided thyme, sea salt, black pepper, nutmeg, and red pepper flakes. Once the Brussels sprouts finish their first turn in the oven, top with the sauce mixture then the reserved pancetta.
- Cover the roasted Brussels sprouts with Gruyère, white cheddar, and parmesan. Return to the oven for an additional 15-20 minutes, or until the cheese begins to turn golden brown.
- While the Brussels sprouts take their second turn in the oven, toast the nuts. Set a saute pan to medium heat on the stovetop (If you're using the same saute pan that you used for the pancetta, make sure to wipe it out really well because the nuts will toast best without excess oil). Add nuts and remaining ½ teaspoon thyme, stirring frequently with a spatula or wooden spoon as they begin to brown and intensify in smell. Once toasted, remove the nuts and thyme from the pan a side dish so that they do not continue to cook. The whole process should take about 5 minutes. Keep in mind that the nuts can go from a lovely golden brown to burnt very quickly, so you'll want to keep a close eye on them as they cook.
- Top the Brussels Sprouts au Gratin with the reserved toasted walnuts and thyme and serve warm.
Nutritional information on Whip & Wander is provided as a courtesy and is approximate only. We cannot guarantee the accuracy of the nutritional information given for any recipe on this site.
- Serving Size: 1 serving
- Calories: 339
- Sugar: 3 g
- Sodium: 68 mg
- Fat: 27 g
- Saturated Fat: 9 g
- Carbohydrates: 11 g
- Fiber: 5 g
- Protein: 16 g
- Cholesterol: 68 mg
Keywords: brussels sprouts, au gratin, French, Gruyere, side dish, cast-iron pan, pancetta
The addition of walnuts, wow! Genius! I will definitely have to make this.
Trish Bozeman says
Ooooh anything with gruyere and I'm a happy girl! We love brussels sprouts, but rarely steer from the trusty olive oil, s&p, and roasted. This looks so creamy and melty and cheesy and DELICIOUS!
I love this unique gratin! All the flavors go great together and I'm a big fan of the walnuts!
Cathleen @ A Taste of Madness says
My mother-in-laws made brussels sprouts over the holidays, and her dad was just saying over and over that brussels sprouts are the worst. So I definitely wouldn't give this to him!! But I am drooling over this myself 🙂
Jacque Hastert says
The combination of flavors is out of the world good. We love brussels sprouts and the addition of the walnuts really packs a crunch!
Ohhh my god girl. This is like, off-the-charts delicious. I absolutely love the tanginess of the Dijon. Not to mention that winning blend of cheeses. What a way to eat Brussels sprouts! <3
I recently bought Brussels sprouts and was not sure what to do as we do not eat much. Your recipe with panceta, walnuts, and cheese looks delicious and must try.
Delicious. Seriously delicious. I may never eat brussels sprouts any other way! I never would have thought to add the nuts but I'm so glad you did, it was just perfect, warm, and completely comforting.
Amy Dong says
Oh my goodness, that dish looks really delicious and that cheesy sauce makes me really hungry. I will definitely make this recipe for myself. Hahaha! 😉
Lesli Schwartz says
I freaking LOVE Brussels sprouts! And adding pancetta and cheese puts this over the top! Your images are stunning!
Stine Mari says
I have a ton of brussels sprouts needing to be eaten so I am definitely making this au gratin this weekend and I can't wait!
Mmmm....that tangy mustard with the rich cheese. Great flavor profile....and the crunch from the nuts another good layer. All on top of my beloved brussels sprouts. Well played!
Jere Cassidy says
Wow, wow, wow, can't remember a brussel sprout recipe that looks and sounds so delicious. The pancetta, gruyere cheese, and walnuts just add to the brussel sprouts flavor. Yum
Roasted Brussels Sprouts are my favorite veggie. I never even thought to make them au gratin. My mind is spinning. I can not wait to try this recipe - looks absolutely amazing!!!