1. Preheat the oven: Preheat your oven to 375°F (190°C). Grease a baking dish and set it aside.

2. Blanch the Brussels sprouts: Bring a large pot of salted water to a boil. Add the Brussels sprouts and cook for about 5 minutes until they are slightly tender. Drain them and transfer to a bowl of ice water to stop the cooking process. Once cooled, drain and set aside.

3. Cook the bacon: In a skillet over medium heat, cook the chopped bacon until crispy. Remove the bacon with a slotted spoon and place it on a paper towel-lined plate to drain excess grease. Set aside.

4. Make the cheese sauce: In the same skillet used for the bacon, melt the butter over medium heat. Add the flour and whisk constantly for about 1-2 minutes until the mixture turns golden brown. Gradually pour in the milk while whisking continuously to avoid lumps. Cook the mixture until it thickens, usually about 5-7 minutes.

5. Add the cheeses: Reduce the heat to low. Stir in the Gruyere and Parmesan cheeses until they melt and the sauce is smooth. Season with nutmeg, salt, and pepper to taste.

6. Combine Brussels sprouts and bacon: Add the blanched Brussels sprouts and cooked bacon to the cheese sauce. Gently toss until the sprouts and bacon are evenly coated.

7. Prepare the breadcrumb topping: In a small bowl, combine the panko breadcrumbs with chopped parsley.

8. Assemble the gratin: Transfer the Brussels sprouts and bacon mixture to the greased baking dish. Sprinkle the breadcrumb mixture evenly over the top.

9. Bake: Place the baking dish in the preheated oven and bake for 25-30 minutes or until the top is golden brown and the gratin is bubbly around the edges.

10. Serve: Remove the gratin from the oven and let it cool for a few minutes before serving. Garnish with additional chopped parsley if desired. Enjoy your Bacon Brussels Sprouts Gratin!

This dish is a delightful combination of crispy bacon, creamy cheese sauce, and tender Brussels sprouts, making it a perfect side dish for any meal or a comforting main course on its own.

1. Preheat the oven: Preheat your oven to 375°F (190°C). Grease a baking dish and set it aside.

2. Blanch the Brussels sprouts: Bring a large pot of salted water to a boil. Add the Brussels sprouts and cook for about 5 minutes until they are slightly tender. Drain them and transfer to a bowl of ice water to stop the cooking process. Once cooled, drain and set aside.

3. Cook the bacon: In a skillet over medium heat, cook the chopped bacon until crispy. Remove the bacon with a slotted spoon and place it on a paper towel-lined plate to drain excess grease. Set aside.

4. Make the cheese sauce: In the same skillet used for the bacon, melt the butter over medium heat. Add the flour and whisk constantly for about 1-2 minutes until the mixture turns golden brown. Gradually pour in the milk while whisking continuously to avoid lumps. Cook the mixture until it thickens, usually about 5-7 minutes.

5. Add the cheeses: Reduce the heat to low. Stir in the Gruyere and Parmesan cheeses until they melt and the sauce is smooth. Season with nutmeg, salt, and pepper to taste.

6. Combine Brussels sprouts and bacon: Add the blanched Brussels sprouts and cooked bacon to the cheese sauce. Gently toss until the sprouts and bacon are evenly coated.

7. Prepare the breadcrumb topping: In a small bowl, combine the panko breadcrumbs with chopped parsley.

8. Assemble the gratin: Transfer the Brussels sprouts and bacon mixture to the greased baking dish. Sprinkle the breadcrumb mixture evenly over the top.

9. Bake: Place the baking dish in the preheated oven and bake for 25-30 minutes or until the top is golden brown and the gratin is bubbly around the edges.

10. Serve: Remove the gratin from the oven and let it cool for a few minutes before serving. Garnish with additional chopped parsley if desired. Enjoy your Bacon Brussels Sprouts Gratin!

This dish is a delightful combination of crispy bacon, creamy cheese sauce, and tender Brussels sprouts, making it a perfect side dish for any meal or a comforting main course on its own.