This Brussels sprouts gratin combines perfectly roasted Brussels sprouts with a rich, cheesy white sauce and a crunchy breadcrumb topping, all cooked in the air fryer. It’s the ultimate side dish for Christmas or Thanksgiving! Oven instructions included.
Creamy Brussels sprouts gratin for Christmas dinner
My family lovingly calls this "Christmas Sprouts Gratin" because I’ve been making it every Christmas for years. It's a fantastic way to use the seasonal British Brussels sprouts, paired with my easy cheese sauce that I also use for cauliflower cheese recipe.
I’ve made this dish so many times, I've perfected the art of the ideal sprouts gratin—a dish worthy of your holiday table. The trick is roasting the Brussels sprouts (or "little cabbages," as we sometimes call them) until they’re nicely caramelized, just like my air fryer roasted Brussels sprouts. The crispy breadcrumb topping is the finishing touch that makes it irresistible. Pair this alongside your holiday roast or a whole roasted cauliflower for the perfect Christmas dinner!
Tips for the Best Brussels Sprouts Au Gratin
- Roast, don’t boil – Roasting Brussels sprouts brings out their natural sweetness and depth of flavor. Skip boiling and go for roasting instead.
- Season with more than just salt and pepper – I like to use chili salt (make your own with ½ teaspoon of garlic powder, onion powder, oregano, mild paprika, and salt). You can also use fajita or taco seasoning for a change.
- Go cheesy – A creamy cheddar cheese sauce adds richness. Or, swap it with Gruyère and Parmesan for a more indulgent flavor.
- Flavored breadcrumb topping – Toss white breadcrumbs with herbs before sprinkling them on top - soo good! Plain breadcrumbs work just as well too for a simpler option.
- Choose the right Brussels sprouts to get that perfectly bubbly, golden top.
Variations: Add banana shallots, bacon, pancetta, or chestnuts for extra savory flair.
How to make Brussels Sprouts gratin in air fryer? Step by Step:
This Christmas sprouts recipe has three easy steps:
Roast the Sprouts: I use a tray that fits into my vortex 8.5l air fryer. Toss Brussels sprouts with oil and chili salt, then roast them in the air fryer for 8-10 minutes until golden.
Prepare the White Sauce: Make a creamy béchamel sauce using my favorite recipe, which I also use for air fryer cauliflower cheese. It’s a familiar flavor everyone loves. For a change I would use a cauliflower mac and cheese sauce or a dauphinoise potatoes creamy sauce.
Assemble and Cook: Arrange the roasted sprouts in a serving dish, pour the white sauce over, and top with breadcrumbs. Then, air fry or oven-bake until golden brown and bubbly. Sprinkle with parsley before serving.
For Air Fryer Instructions: Place the assembled dish in the air fryer basket and air fry at 180C for about 10-12 minutes or until golden brown.
For Oven Instructions: Preheat the oven to 220C/200C fan/gas 7. Bake the dish in the center of the oven for 20-25 minutes or until golden brown and bubbling. Allow it to rest for at least 10 minutes before serving.
Make-Ahead Brussels Sprouts Gratin Dish for Christmas
This recipe is perfect for meal prep! Roast the Brussels sprouts, prepare the cheese sauce, and assemble your make-ahead Brussels sprouts gratin in a baking dish. Cover and refrigerate for up to 24 hours. About 15-20 minutes before serving, transfer the dish to the air fryer to finish cooking. If you’re using the oven, bake it at 180°C (350°F) for about 30 minutes until bubbly and golden. It's ideal for busy holiday preparations!
Serving Suggestions
I love Brussels sprouts gratin as both a side dish or a main course, especially during the holidays. Simply adjust the portion size! It pairs beautifully with a Christmas vegetable traybake, air fryer crispy potato slices, lentil loaf, curried butternut squash soup, easy garlic knots, or Christmas coleslaw.
For more inspiration, explore my collection of 50+ vegetarian Christmas dinner recipes to find perfect pairings for this festive gratin!
Recipe FAQ's
Yes, frozen Brussels sprouts can be used. However, you’ll need to add a few extra minutes to the roasting time in the air fryer or oven to get those crispy, caramelized edges. After that, follow the recipe as usual for the gratin.
Absolutely! You can substitute evaporated milk or use extra whole milk to achieve a creamy texture. Just cook the sauce longer to thicken it until you reach your desired consistency.
More Brussels sprouts recipes
- Shaved Brussels sprouts salad
- Christmas Veg gratin
- Air fryer roasted Brussels sprouts
- Christmas vegetable tray bake
Homemade Brussels sprouts au gratin recipe
Ingredients
- 500 g Brussels sprouts trimmed and halved if large
- 2 teaspoon olive oil
- 2 teaspoon chilli salt ***( see notes for substitutions)
Cheese Sauce
- 2 tablespoon butter
- 2 tablespoon plain flour
- 250 ml double cream
- 200 ml whole milk
- 1 teaspoon dijon mustard
- salt and pepper to taste
- 75 g mature cheddar grated
On the top
- 50 g dried bread crumbs
- 2 tablespoon parsley
Instructions
- Toss the Brussels sprouts with oil and salt. Air fry at 180C for 8-10 minutes until roasted and tender.500 g Brussels sprouts, 2 teaspoon olive oil, 2 teaspoon chilli salt
- Simultaneously, make a cheese sauce.Heat butter in a pan. When melted, add the flour and cook continuously in low flame to create a roux.2 tablespoon butter, 2 tablespoon plain flour , 200 ml whole milk, 250 ml double cream, salt and pepper to taste, 75 g mature cheddar
- Then add the milk and cream a little at a time first and continue to whisk until thick.
- Add the dijon mustard, and stir and cook until the sauce bubbles.Switch off the flame and add cheddar cheese.1 teaspoon dijon mustard
- Transfer the roasted sprouts to an oven dish. Pour the cheese sauce over until fully coated. Top with the breadcrumbs over the top.50 g dried bread crumbs
Air frying
- Transfer the dish to the air fryer basket. Air fry at 180C for 10-12 minutes until the sauce is bubbling and the top is brown.
Baking in the Oven
- Preheat the oven to 200C. If you would like to bake, place the the dish in the middle rack of the oven. Bake for 20-25 minutes until sauce is bubbling and the top is brown.
- Garnish with chopped fresh parsley.2 tablespoon parsley
Notes
Tips for the Best Brussels Sprouts Au Gratin
- Roast, don’t boil – Roasting Brussels sprouts brings out their natural sweetness and depth of flavor. Skip boiling and go for roasting instead.
- Season with more than just salt and pepper – I like to use chili salt (make your own with ½ teaspoon of garlic powder, onion powder, oregano, mild paprika, and salt). You can also use fajita or taco seasoning for a change. ***
- Go cheesy – A creamy cheddar cheese sauce adds richness. Or, swap it with Gruyère and Parmesan for a more indulgent flavor.
- Flavored breadcrumb topping – Toss white breadcrumbs with herbs before sprinkling them on top - soo good! Plain breadcrumbs work just as well too for a simpler option.
- Choose the right Brussels sprouts to get that perfectly bubbly, golden top.
Emily cooper says
Made it last night and this Sprouts gratin was simply a hit …thank you.