After a few minutes in boiling water, Brussels sprouts should be crisp-tender, not soft. That quick blanch gives them a head start before they go into the oven, so they finish cooking beneath the cheese sauce without turning limp. I like that contrast in this White Cheddar Brussels Sprouts Gratin with Smoked Bacon: tender sprouts, a creamy sharp-cheddar sauce, and a crisp, buttery panko top.
The sauce gets its body from a short roux, then whole milk and cream make it rich enough to cling to the sprouts. Smoked bacon brings a salty bite, while Dijon keeps the cheese from tasting flat. You don’t need to fuss with layers; the sprouts and bacon go right into the baking dish, and the sauce gets poured over them.
When the edges bubble and the panko turns golden, the gratin is ready for a short rest. That gives the sauce a chance to settle around the sprouts instead of running across the plate.
Kitchen Note
Drain the sprouts thoroughly after blanching. Extra water clinging to the leaves can loosen the sauce in the oven, so give them a good shake in the colander before they go into the dish.
Save this white cheddar Brussels sprouts gratin for a cozy dinner or holiday table: crisp smoked bacon, bubbling cheese sauce, and a golden panko top.
Why the White Cheddar Goes In After the Sauce Leaves the Heat
A smooth cheese sauce starts with a properly thickened base, but the cheese itself doesn’t need to cook. First, the flour and butter make a roux; milk and cream whisked in gradually turn it into a sauce that coats the back of a spoon. Once that texture is there, take the saucepan off the heat before adding Dijon, seasoning, and cheddar.
Cheddar can turn grainy or oily if it gets too hot while melting. Off the burner, it softens into the warm sauce without the direct heat continuing to tighten the proteins. Stir until the sauce looks even and glossy, with no visible shreds left. If you see a few streaks, keep stirring gently rather than putting the pan back over the burner.
This matters especially in a gratin, where the sauce will heat again in the oven. The oven’s job is to warm everything together and brown the topping, not to finish melting cheese that was added over high heat. Keeping those stages separate gives you a creamy sauce around the sprouts.
What the Smoke, Sharp Cheddar, and Panko Each Bring to This Gratin
- Brussels sprouts — Choose firm sprouts with tightly held leaves; loose or yellowing outer leaves are a sign they’ve been sitting around. Trimming and halving helps them cook evenly during the brief boil and gives the sauce plenty of cut surfaces to cling to.
- Thick-cut smoked bacon — The thicker pieces stay substantial after crisping and bring smoke to the creamy sauce. Regular smoked bacon works if that’s what you have, though the pieces will be smaller and less meaty. The bacon is already salty, which is one reason the seasoning in the sauce stays measured.
- Sharp white cheddar — Sharp cheddar brings tang that stands up to the sprouts and cream. A block you shred yourself tends to melt more smoothly than pre-shredded cheese, which may contain anti-caking starch; pre-shredded is convenient, but the sauce may not look quite as silky.
- Whole milk and heavy cream — Whole milk keeps the sauce pourable, while cream adds richness and helps it coat the vegetables. Using lower-fat milk in place of whole milk makes a thinner, less full-bodied sauce; keep the cream in the mix for the texture this gratin is meant to have.
- All-purpose flour and butter — Together they form the roux that thickens the dairy before the cheese goes in. Whisk the flour into fully melted butter so you don’t leave dry pockets in the base.
- Panko breadcrumbs — Panko gives the topping a light, crisp texture instead of a dense crumb layer. Tossing it with melted butter helps it brown evenly across the gratin.
- Dijon mustard — Dijon adds a subtle tang that keeps the cheddar sauce from tasting one-note. It blends into the sauce without making the finished dish taste strongly of mustard.
The Four Stages That Get This Gratin to the Table
Blanch the Sprouts Until They Still Have a Little Bite
Heat the oven to 375°F and coat a 9×13-inch baking dish with nonstick cooking spray. Bring 3 quarts of water to a boil in a 6-quart pot, add the trimmed, halved Brussels sprouts, and cook them for 4 to 5 minutes. Look for bright green sprouts that yield slightly when pierced but aren’t soft. Drain them well so water doesn’t collect beneath the sauce.
Cook the Bacon Until Crisp
Set the diced thick-cut smoked bacon in a 12-inch skillet over medium heat. Cook for 6 to 8 minutes, stirring as needed, until the pieces are crisp and browned. If they’re still floppy, give them another moment; chewy bacon loses its texture among the soft sprouts. Transfer the crisp pieces to a paper towel-lined plate.
Thicken the Dairy Before Adding Cheddar
Melt 3 tablespoons of butter in a 3-quart saucepan over medium heat, whisk in the flour, and cook for 1 minute. Gradually whisk in the milk and cream so the sauce stays smooth, then cook for 4 to 6 minutes, whisking often. It should thicken enough to coat the back of a spoon; if it still runs off like milk, keep whisking as it cooks. Remove the pan from the heat, then stir in the Dijon, kosher salt, black pepper, and shredded cheddar until smooth.
Top and Bake Until the Edges Bubble
Combine the drained sprouts and cooked bacon in the prepared baking dish, then pour the cheese sauce over them. Melt the remaining butter and stir it with the panko; scatter the crumbs evenly across the top. Bake for 20 to 25 minutes, until the sauce bubbles around the edges and the topping is golden brown. Rest the gratin for 10 minutes before serving so the sauce can settle.
Three Ways to Change the Smoke, Cheese, or Flour
Make It Vegetarian by Leaving Out the Bacon
Skip the bacon and its skillet step, then combine the sprouts with the cheese sauce in the baking dish. The gratin will lose the smoky, salty bites, but the sharp cheddar and Dijon still give the sauce plenty of flavor.
Use Gruyère for a Nuttier Cheese Sauce
Replace the sharp white cheddar with the same amount of shredded Gruyère. It melts into a smooth sauce and gives the gratin a mellow, nutty character, with less of cheddar’s sharp tang.
Make a Gluten-Free Version
Use a 1:1 gluten-free all-purpose flour blend in place of the all-purpose flour and gluten-free panko instead of regular panko, keeping the listed quantities. Some flour blends thicken at a slightly different pace, so judge the sauce by its spoon-coating texture rather than the clock alone.
Storage and Reheating
- Refrigerator: Store covered within 2 hours and keep for 3 to 4 days. The panko softens as it sits, while the sauce firms up when cold.
- Freezer: Freezing isn’t recommended; the cream-and-cheese sauce may separate, and the sprouts soften further after thawing.
- Reheating: Warm portions in a 350°F oven, covered with foil, until hot throughout; uncover near the end if you want to crisp the top again. Heat leftovers to 165°F, and avoid relying on the microwave for a crisp topping.
Questions That Come Up Before This Sprouts Gratin Goes in the Oven
White Cheddar Brussels Sprouts Gratin with Smoked Bacon
Ingredients
Equipment
Method
- Heat the oven to 375°F.
- Coat a 9x13-inch baking dish with nonstick cooking spray.
- Bring the water to a boil in a 6-quart pot, add the Brussels sprouts, and cook for 4 to 5 minutes until crisp-tender.
- Drain the Brussels sprouts well.
- Cook the bacon in a 12-inch skillet over medium heat for 6 to 8 minutes until crisp.
- Transfer the bacon to a paper towel-lined plate.
- Melt 3 tablespoons of the butter in a 3-quart saucepan over medium heat.
- Whisk in the flour and cook for 1 minute.
- Gradually whisk in the milk and cream.
- Cook for 4 to 6 minutes, whisking often, until the sauce thickens enough to coat the back of a spoon.
- Remove the sauce from the heat.
- Stir in the Dijon, salt, pepper, and cheddar until smooth.
- Combine the Brussels sprouts and bacon in the baking dish.
- Pour the sauce over the Brussels sprouts and bacon.
- Melt the remaining 2 tablespoons butter.
- Stir the melted butter with the panko.
- Scatter the panko mixture evenly over the gratin.
- Bake for 20 to 25 minutes until the sauce is bubbling around the edges and the topping is golden brown.
- Let the gratin rest for 10 minutes before serving.