Easy Bacon Brussels Sprouts Gratin: 45-Minute Holiday Side

If you’re looking for a comforting side dish for the holiday table, this Bacon Brussels Sprouts Gratin is a delicious choice. Tender Brussels sprouts are paired with savory bacon and a rich, creamy topping for a dish that feels warm, hearty, and perfect for sharing.

I love making this gratin for Thanksgiving and family dinners because it turns simple Brussels sprouts into something extra special. It is a cozy addition to any fall or winter meal and pairs beautifully with roasted meats and other holiday favorites. Serve it warm from the oven for a comforting side everyone will want to scoop onto their plate.

Why You’ll Love This Recipe

• Redemption arc: This dish turns Brussels sprouts into a side people fight over at the dinner table.
• Two-step method: Roasting first gives the sprouts a head start before the creamy bake.
• Holiday hero: This creamy holiday vegetable side needs little attention while you manage the rest of the meal.
• Pork fat: This cheesy Brussels sprouts gratin with bacon pairs crisp pork with sharp cheddar and cream.
• Make-ahead potential: You can cook the bacon and grate the cheese before you start roasting the sprouts.

Tools You’ll Need

Nothing fancy, I promise.

• 9×13 baking dish: Use a wide dish so the sprouts roast instead of steam.
• Large mixing bowl: Whisk the cream and egg mixture without splashing.
• Cheese grater: Grate your own cheese for smoother melting.
• Whisk: Beat the egg and cream until fully combined.
• Measuring cups and spoons: Measure the cream, cheese, oil, and seasonings.

Ingredients

• 1 1/2 pounds brussels sprouts, halved Try to pick ones that are roughly the same size so they cook evenly. Brussels sprouts are essentially tiny cabbages, and they need high heat to sweeten up.
• 8 oz. bacon, cooked and crumbled Thick-cut works best because it holds its crunch inside the creamy sauce.
• 1 cup sharp cheddar cheese, grated Adds the salty, tangy punch that cuts through the heavy cream.
• 1/2 cup fontina cheese, grated, optional Fontina melts beautifully, but Gruyere or even mozzarella works if you cannot find it.
• 3/4 cup heavy cream Do not use milk. Milk will curdle and leave you with a watery, broken mess.
• 2 tablespoons extra-virgin olive oil Just enough to coat the sprouts for their initial roast.
• 1 egg This acts as the binder, turning the cream and cheese into a cohesive custard instead of soup.
• 1 sprig rosemary, minced Fresh rosemary cuts through the heavy fat and adds an earthy note.
• 1 teaspoon garlic powder Distributes evenly through the sauce without harsh raw garlic bites.
• 1 teaspoon onion powder Adds a savory backbone to the cream mixture.
• 1/2 teaspoon red pepper flakes, optional Highly recommended for a tiny kick of heat.
• kosher salt and freshly ground pepper, to taste Salt generously before roasting; the sprouts need it to wake up.

How To Make Bacon Brussels Sprouts Gratin

Let the oven do the heavy lifting while you shred the cheese and try not to eat all the bacon.

1. Preheat: Preheat oven to 400º F. Do not skip letting the oven fully preheat, or your sprouts will steam instead of browning.
2. Roast the sprouts: Toss brussel sprouts in olive oil and season generously with salt and pepper. Place them in a large baking dish and roast for 15-20 minutes, or until semi-softened. Do not skip this pre-roast, or your sprouts will be hard and bitter while your cheese burns.
3. Mix the sauce: In a large bowl, whisk together egg, heavy cream, rosemary, garlic powder, onion powder and red pepper flakes (if using), then stir in cheeses. Whisk the egg and cream thoroughly before adding the cheese so you do not end up with scrambled egg bits.
4. Combine and top: Remove brussel sprouts from oven and add 3/4 bacon to the baking dish. Pour cheese mixture over the top and stir everything together, then top with remaining bacon. Stir gently so you do not mash the softened sprouts into paste.
5. Bake the gratin: Reduce oven temperature to 350º, return baking dish to oven and bake for 20-25 minutes, or until cheese is bubbly and just set. If the top browns too fast, loosely tent it with foil.
6. Rest: Remove from oven and let cool 5 minutes before serving. If you dish it out immediately, the sauce will run everywhere. Give it a minute to pull itself together.

Seasoning and Taste as You Go

You cannot really taste raw egg and heavy cream safely, so rely on smelling your spice mix and properly salting the sprouts beforehand.

• Too flat? You probably skimped on the salt during the roasting phase. A tiny pinch of flaky salt on top before serving helps.
• Too salty? Bacon and cheddar carry a lot of sodium. If you know your bacon is incredibly salty, pull back on the kosher salt you use on the sprouts.
• Needs depth? A squeeze of lemon juice over your own plate brightens the whole situation up.

Make It Yours

You can tweak this heavily based on what is sitting in your cheese drawer.

• Protein swap: Swap the bacon for diced pancetta or crumbled Italian sausage for a different savory note.
• Vegetarian version: Omit the bacon and add smoked paprika or toasted walnuts for smoky crunch.
• Cheese swap: Gruyere or Gouda can replace Fontina for a nuttier profile. [suggested substitution, untested]
• Spice level: Double the red pepper flakes or add cayenne to the cream mixture for more heat.

Perfect Pairings

A heavy dish needs balance, but let us be honest, you are eating this at a feast.

• Roast turkey or a thick steak gives this gratin a strong main course beside the creamy sprouts.
• A crisp green salad with acidic dressing cuts through the heavy cream and bacon.
• A dry white wine such as Sauvignon Blanc balances the rich dairy.
• If you host a crowd, serve Easy Baked Brie for Thanksgiving and Christmas before dinner so guests have an appetizer while you cook.

Brussels Sprouts Gratin

This bacon Brussels sprouts gratin combines roasted Brussels sprouts, crisp bacon, sharp cheddar, optional fontina, heavy cream, egg, and rosemary in one bubbling holiday side dish. The sprouts roast at 400°F before the cheese mixture bakes at 350°F for 20 to 25 minutes. Make this bacon Brussels sprouts gratin for Thanksgiving, Christmas, or any dinner that needs a rich vegetable side.

Print Recipe Pin Recipe

Total Time 45 minutes mins

Servings: 6 servings

Course: Dinner

Cuisine: American

Ingredients Equipment Method

Ingredients

  

• 1 1/2 pounds brussels sprouts halved
• 8 oz . bacon cooked and crumbled
• 1 cup sharp cheddar cheese grated
• 1/2 cup fontina cheese grated, optional
• 3/4 cup heavy cream
• 2 tablespoons extra-virgin olive oil
• 1 egg
• 1 sprig rosemary minced
• 1 teaspoon garlic powder
• 1 teaspoon onion powder
• 1/2 teaspoon red pepper flakes optional
• kosher salt and freshly ground pepper, to taste

Equipment

• 9×13 baking dish
• large mixing bowl
• Cheese grater
• Measuring cups and spoons

Method

 

1. Preheat the Oven

   Preheat the oven to 400°F (200°C). Allow the oven to fully preheat before roasting so the Brussels sprouts begin browning properly rather than steaming.
2. Roast the Brussels Sprouts

   Place the Brussels sprouts in a baking dish and toss them with the olive oil, kosher salt, and freshly ground black pepper until evenly coated.

   Spread the sprouts into an even layer and roast for 15–20 minutes, or until they have softened slightly and are beginning to develop some color. They will continue cooking in the gratin.
3. Make the Cheese Sauce

   While the Brussels sprouts roast, add the egg, heavy cream, rosemary, garlic powder, onion powder, and red pepper flakes, if using, to a large bowl.

   Whisk thoroughly until the egg and cream are fully combined and the mixture is smooth. Stir in the cheeses until evenly incorporated.
4. Combine and Add the Topping

   Remove the partially roasted Brussels sprouts from the oven. Add ¾ of the cooked bacon to the baking dish and gently stir to distribute it among the sprouts.

   Pour the cheese mixture evenly over the Brussels sprouts and bacon. Stir gently to make sure the sauce coats the vegetables without breaking them apart. Sprinkle the remaining bacon evenly over the top.
5. Bake the Gratin

   Reduce the oven temperature to 350°F (175°C). Return the baking dish to the oven and bake for 20–25 minutes, or until the cheese is bubbling and the center of the gratin is set.

   If the top begins to brown too quickly, loosely cover the dish with foil for the remainder of the baking time. For food safety, the egg-based center should reach 160°F (71°C) when checked with a food thermometer.
6. Rest Before Serving

   Remove the gratin from the oven and let it rest for about 5 minutes before serving. The creamy sauce will continue to thicken as it cools slightly, making the gratin easier to serve.