Brussels Sprouts Gratin with Walnut Crumble and Cheddar Cheese
This Brussels sprouts gratin transforms humble sprouts into an elegant side dish with layers of rich bechamel sauce and sharp cheddar cheese. Topped with a crunchy walnut crumble featuring Parmesan, panko, and thyme, it delivers contrasting textures and nutty flavors. The sprouts are briefly boiled to retain some firmness before being smothered in creamy sauce and baked until golden. Perfect for holiday dinners or special occasions when you want to your vegetable game, this gratin makes Brussels sprouts irresistible even to skeptics.
Ingredients
- ½ teaspoon salt, plus more to taste
- 1 pound Brussels sprouts, trimmed
- ½ stick butter
- ¼ cup all-purpose flour
- 2 cups milk
- ¼ teaspoon nutmeg, grated
- 1 garlic clove, grated
- 1 tablespoon wholegrain mustard
- 1 cup cheddar cheese, freshly grated
- pepper, to taste(optional)
- ½ cup panko breadcrumbs
- ½ cup Parmesan, freshly grated
- ½ cup walnuts, chopped
- 1 teaspoon dried thyme
Instructions
- 1
Bring a pan of water to a boil
- 2
Add salt and cook Brussels sprouts for 5-8 minutes until soft but still firm
- 3
Drain the sprouts well and set aside
- 4
Melt butter in a small saucepan over medium heat
- 5
Whisk in flour continuously and cook until golden, about 2 minutes
- 6
Whisk in milk, nutmeg, and garlic
- 7
Reduce heat to medium low and whisk until sauce thickens, about 5-10 minutes
- 8
Remove pan from heat and stir in mustard and cheddar cheese
- 9
Season with salt and pepper once cheese has melted
- 10
Preheat oven to 400 F
- 11
Combine breadcrumbs, Parmesan, walnuts, and thyme in a mixing bowl
- 12
Add Brussels sprouts to an oven-proof 9x9-inch baking dish
- 13
Cover sprouts evenly with bechamel sauce
- 14
Scatter walnut crumble on top
- 15
Bake until golden, about 20-25 minutes
- 16
Rest outside oven for 5 minutes before serving
Tips
Don't overcook the Brussels sprouts in the initial boiling stage - they'll continue cooking in the oven and become mushy if too soft initially.
Let the gratin rest for 5 minutes after baking to allow the sauce to set slightly, making it easier to serve clean portions.
Toast the walnuts lightly before chopping for extra depth of flavor in the crumble topping.
Good to Know
Refrigerate covered for up to 3 days. Reheat in 350F oven until warmed through.
Assemble completely up to 1 day ahead, cover and refrigerate. Add 10 minutes to baking time if baking from cold.
Serve immediately while hot as a side dish. Pairs well with roasted meats or holiday dinners.
Common Mistakes
Don't skip the resting period after baking to avoid runny sauce when serving
Ensure Brussels sprouts are well-drained after boiling to prevent watery gratin
Don't add cheese to hot bechamel or it may curdle - remove from heat first
Substitutions
Dairy-Free Swaps
Gluten-Free Swaps
General Alternatives
FAQ
Can I make this gratin ahead of time?
Yes, assemble completely up to 1 day ahead and refrigerate covered. Add about 10 minutes to the baking time if baking straight from the refrigerator.
What if I don't like Brussels sprouts?
You can substitute cauliflower florets, broccoli, or even sliced potatoes. Adjust cooking times accordingly - potatoes will need longer initial cooking.
How long will leftovers keep?
Store covered in the refrigerator for up to 3 days. Reheat in a 350F oven until warmed through, about 15-20 minutes.