Ingredients:

  • 1 kg (2.2 lbs) Brussels Sprouts, trimmed and halved
  • 50 g (1.8 oz) Pancetta, diced
  • 1 tbsp (15 ml) Olive Oil
  • Salt and Black Pepper, to taste
  • 60 g (4 tbsp) Unsalted Butter (for sauce)
  • 60 g (½ cup) All-Purpose Flour
  • 600 ml (2 ½ cups) Whole Milk, warmed
  • ¼ tsp Freshly Grated Nutmeg
  • 1/8 tsp Cayenne Pepper (optional)
  • 150 g (5 oz) Gruyère Cheese, grated
  • 50 g (1.8 oz) Parmigiano-Reggiano, finely grated (for sauce)
  • 60 g (1 cup) Panko Breadcrumbs
  • 30 g (2 tbsp) Unsalted Butter, melted (for topping)
  • 25 g (¼ cup) Extra Parmigiano-Reggiano, finely grated (for topping)

Instructions:

  1. Blanch the Sprouts: Bring a large pot of salted water to a rolling boil. Add the trimmed and halved Brussels sprouts and cook for 3–4 minutes until they are bright green and slightly tender (al dente). Immediately drain and plunge them into iced water to halt the cooking process. Drain well and set aside.
  2. Render the Pancetta: Heat the olive oil in a skillet over medium heat. Add the diced pancetta and cook until crispy and golden brown. Remove the pancetta with a slotted spoon, reserving 1–2 tablespoons for garnish, and reserve the rendered fat in the pan.
  3. Make the Roux: Add the butter (if needed) or use the reserved pancetta fat in a heavy-bottomed saucepan over medium heat. Whisk in the flour until a smooth paste (the roux) forms. Cook for 1–2 minutes, stirring constantly, until pale golden.
  4. Add Milk: Gradually whisk in the warm milk, adding a small amount at a time, ensuring each addition is fully incorporated. Continue whisking until the sauce is smooth and thick (about 5–8 minutes).
  5. Season and Add Cheese (Mornay Sauce): Remove the sauce from the heat. Stir in the nutmeg, cayenne, salt, and pepper. Gradually fold in the grated Gruyère and 50g of Parmigiano-Reggiano until completely melted and the sauce is smooth and velvety. Taste and adjust seasoning.
  6. Combine the Filling: Gently toss the blanched sprouts and most of the crispy pancetta with the Mornay sauce, ensuring everything is well coated.
  7. Assemble: Preheat the oven to 200°C (400°F). Lightly butter a 9x13 inch casserole dish. Pour the sprout mixture into the prepared dish, leveling the surface.
  8. Prepare and Apply Topping: In a small bowl, combine the panko breadcrumbs, melted butter, and the remaining 25g of Parmigiano-Reggiano. Sprinkle this mixture evenly over the sprouts.
  9. Bake: Bake for 20–25 minutes, or until the sauce is bubbling around the edges and the topping is deeply golden brown and crispy.
  10. Rest and Serve: Let the gratin rest for 5–10 minutes before serving. Garnish with the reserved crispy pancetta.