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Bacon Brussels Sprouts Gratin

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.
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Total Time 45 minutes
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

  • 9x13 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.