Brussels Sprouts Gratin

Instructions

1. Prepare the Brussels sprouts
   Preheat oven to 375°F (190°C). Bring a large pot of salted water to a boil. Add Brussels sprouts and blanch for 3 minutes until bright green and slightly tender. Drain well and pat dry with paper towels.
2. Sauté the aromatics
   Heat olive oil in a large oven-safe skillet over medium heat. Add minced garlic and sauté for 1 minute until fragrant but not browned. Remove the Brussels sprouts and garlic from the skillet and set aside.
3. Make the béchamel sauce
   In the same skillet, melt butter over medium heat. Add flour and whisk continuously for 1-2 minutes to make a roux. Gradually whisk in warm milk and heavy cream. Continue to cook, stirring constantly, until the sauce thickens enough to coat the back of a spoon, about 5-7 minutes. Season with salt, pepper, and nutmeg.
4. Add the cheese
   Reduce heat to low and stir in 3/4 cup of the Gruyère cheese and 1/4 cup of the Parmesan cheese until melted and smooth. Return the Brussels sprouts to the skillet and gently fold to coat with the cheese sauce.
5. Prepare the topping
   In a small bowl, combine panko breadcrumbs, remaining Gruyère and Parmesan cheeses, thyme leaves, and a drizzle of olive oil. Mix well until the breadcrumbs are moistened.
6. Bake the gratin
   Sprinkle the breadcrumb mixture evenly over the Brussels sprouts. If not using an oven-safe skillet, transfer the Brussels sprouts mixture to a greased 9x13 inch baking dish before adding the topping. Bake in the preheated oven for 20-25 minutes until the top is golden brown and the sauce is bubbling around the edges.
7. Rest and serve
   Remove from the oven and let rest for 5 minutes before serving. The gratin will be extremely hot straight from the oven, and the short rest allows the sauce to set slightly for easier serving.