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A hearty side dish that combines gourmet flavor with healthy vegetables is hard to find, but this Brussel sprouts gratin recipe fits the bill. Loaded with creamy cheese and crispy bacon, this savory dish is so indulgent, it’ll make you forget you’re eating veggies!
I might be biased, but I think that Brussels sprouts are one of those vegetables that even the pickiest eaters can love. They’re such versatile ingredients and work well with lots of different flavors. They can be shaved for salads, fried crispy, or even simply roasted and glazed, and they’ll taste delicious every time. Even those who notoriously skip over the veggies during dinner won’t be able to resist this Brussel sprout gratin recipe.
Brussels sprouts and carrots are smothered in a cheesy, flavorful sauce filled with robust mustard and smokey bacon, and the whole thing gets a crispy, golden parmesan cheese breadcrumb crust on top. It’s an ideal dish for the holidays, especially if you’re trying to sneak more greens onto your kids’ plates. Plus, it’s super easy — even if you decide to make your own homemade whole grain mustard. Grab your ingredients and read further to make this impressive recipe!
INGREDIENT NOTES AND SUBSTITUTIONS
- Brussels Sprouts – Be sure to trim and cut your sprouts in half for this recipe. You could chop them a bit smaller if you prefer!
- Carrots – Peeled and sliced whole carrots or baby carrots will work. You may also use parsnips or turnips instead.
- Bacon – The best way to serve vegetables is with bacon! This adds a wonderfully bold savory flavor to the entire dish. Feel free to use pancetta instead.
- Red Onion – I always like to include onion for an extra depth of flavor. Shallots may be used instead.
- Garlic – Mince whole cloves of garlic for this recipe.
- All-Purpose Flour – This will help thicken the dish and keep everything together for a distinct casserole texture.
- Heavy Cream – You can substitute with half and half.
- Dijon Mustard – This will really complement the flavors of bacon and Brussels sprouts. A coarse ground mustard can be substituted.
- Panko Bread Crumbs – Necessary to take this dish from cooked veggies to Brussel sprout gratin! Any bread crumbs that you enjoy will work, or you could even make your own!
- Parmesan Cheese – Plenty of freshly-shredded cheese makes this dish irresistible. Other cheeses can be added or swapped in, like mozzarella, gouda, asiago, or Gruyère.
HOW TO MAKE BRUSSEL SPROUT GRATIN
- Prep For Cooking. Preheat your oven to 400°F and grease a 1 ½-quart casserole or au gratin dish with cooking spray.
- Cook Veggies. Generously salt and boil a large saucepan of water. Cook Brussels sprouts and carrots until tender, about 5 minutes. Drain water immediately (see notes) and leave vegetables in pan.
- Crisp Bacon. Cook chopped bacon in a large skillet until crisp. Transfer to a bed of paper towels and leave the bacon fat in the skillet.
- Saute Onion. Add red onion to the bacon fat and sauté for about a minute before adding garlic, salt, and pepper. Sauté for a minute, then stir in flour.
- Combine Ingredients. Add Brussels sprouts and carrots to the skillet and mix all ingredients together, including the cooked bacon. Stir in half of your cheese.
- Make Sauce. Whisk together your heavy cream and mustard in a small bowl.
- Assemble & Bake. Add the veggie mixture to your prepared casserole dish and pour the sauce evenly over all of it. Sprinkle breadcrumbs and remaining cheese on top, then bake for 20 minutes or until the top is golden brown.
What is “Au Gratin” in Cooking?
If a dish is considered “au gratin,” that usually means that it is baked with browned breadcrumbs or cheese on top. In this case, there’s both!
Anything can be made au gratin, including potatoes and other vegetables. Kick it up a notch with protein like this gratin turkey green bean casserole does.
What Pairs Well With Brussels Sprouts?
You’ll notice that mustard is a major ingredient in this Brussel sprout gratin recipe, and that’s because sprouts and mustard go very well together in most dishes. Mustard’s stark tanginess balances the bold, earthy taste of the Brussels sprouts.
It’s also popular to cook these veggies with ingredients that can infuse and add flavor to them, like savory bacon or sweet maple syrup, or honey.
When are Brussels Sprouts in Season?
From late summer to early spring is when Brussels sprouts typically thrive. Since they’re always in season during the winter months, they’re often served at holiday meals in a variety of delicious forms.
Can You Substitute Baby Carrots for Carrots?
Yes, you can! About 6 to 8 baby carrots should equal one whole carrot. They taste the same, and you don’t have to worry about washing or peeling baby carrots!
This recipe post, originally published on Kevin Is Cooking October, 2019, has been updated with new content, photos and/or video in December, 2022.
Brussels Sprouts Gratin
- 1 1/2 lbs Brussels sprouts trimmed and halved
- 2 carrots peeled and sliced (about 2 cups), or baby carrots
- 6 slices bacon chopped
- 1 tbsp butter
- 1 red onion diced (about 1 cup)
- 1/2 tsp kosher salt
- 1/2 tsp black pepper
- 3 cloves garlic minced
- 1 tbsp all-purpose flour
- 1 cup Parmesan cheese 4 oz, shredded
- 1 cup heavy cream or half and half
- 1 tbsp dijon mustard or coarse ground mustard
- 1/2 cup Panko bread crumbs
- Preheat oven to 400°F. Coat a 1 1/2-quart casserole or au gratin dish with oil or coking spray.
- In a large saucepan of heavily salted boiling water, cook Brussels sprouts and carrots for 5 minutes or until fork tender. Drain, discarding water, and return vegetables to saucepan. Set aside.
- In a large skillet over medium heat render bacon until crisp. Transfer bacon to paper towels to drain, reserving the bacon fat in skillet. Add red onion to skillet and sauté for a minute. Add garlic, kosher salt and pepper and sauté another minute. Stir in flour and cook for another minute.
- Add the sprouts and carrots to the skillet and toss with the onion mixture and crisp bacon. Stir in half of the cheese, tossing to coat. Spoon Brussels sprouts mixture into the prepared casserole dish.
- In a small bowl whisk together the heavy cream and mustard. Pour evenly over Brussels sprouts mixture. Sprinkle Panko and remaining half of cheese over Brussels sprouts mixture. Bake for 20 minutes or until mixture is bubbling and topping is golden brown.
- Immediately drain the Brussels sprouts and carrots to best keep the bright color.
- I often times use the baby carrots instead of large so I don’t have to peel them!
- Feel free to use pepper bacon or even pancetta instead of bacon.
- You may substitute shallots for th ered onion.
- I also use asiago, Gruyère or a mixture of these cheeses instead of the parmesan, they’re a great substitute.
- A coarse grain mustard (like my homemade version) is a great substitute for the dijon.
The information shown is an estimate provided by an online nutrition calculator. It should not be considered a substitute for a professional nutritionist’s advice.