Preparing the Bolognese Sauce

1. Sauté the Vegetables and Pancetta: In a large saucepan, melt the butter over medium heat. Add the pancetta, onion, celery, and carrot. Cook until the onion becomes translucent and pale gold.
2. Brown the Meats: Incorporate the ground beef, pork, and Italian sausage into the saucepan. Increase the heat to high and cook until the meats are browned. Sprinkle in the ground clove, cinnamon, and black pepper.
3. Add Tomatoes and Simmer: Stir in the chopped tomatoes. Once the mixture begins to simmer, reduce the heat to low. Cover the saucepan and let the sauce cook slowly, stirring occasionally, for about 3 hours. If the sauce appears too dry during this time, add a bit of water or beef broth as needed.
4. Finish with Milk: Pour in the whole milk and season with sea salt. Continue to simmer gently for an additional 30 minutes. Once done, set the Bolognese sauce aside.

Preparing the Béchamel Sauce

1. Warm the Milk: In a small saucepan, heat the milk until it’s just about to boil. Then, remove it from the heat and set aside.
2. Create the Roux: In a separate saucepan, melt the butter over medium heat. Add the flour, whisking continuously, and cook until the mixture turns a light golden color, indicating the formation of a roux.
3. Combine and Thicken: Gradually pour the warmed milk into the roux, whisking constantly to prevent lumps. Continue to cook and stir until the sauce thickens to a creamy consistency. Remove from heat and set aside.

Assembling the Lasagna

1. Preheat the Oven: Set your oven to 375°F (190°C).
2. Prepare the Noodles: Cook the lasagna noodles according to the package instructions. Once done, drain and lay them out on a clean kitchen towel to prevent them from sticking together.
3. Layer the Components: In a 13×9-inch baking dish, spread a thin layer of the Bolognese sauce at the bottom. Place a layer of noodles over the sauce. Spread a portion of the Béchamel sauce over the noodles, followed by a sprinkle of grated Parmesan cheese. Repeat this layering process until all components are used, finishing with a layer of Béchamel sauce and a generous sprinkle of Parmesan on top.
4. Bake: Cover the baking dish with aluminum foil and place it in the preheated oven. Bake for 20 to 30 minutes, or until the top is lightly browned and the dish is bubbly.
5. Rest and Serve: Remove the lasagna from the oven and let it rest for 5 to 10 minutes before serving. This allows the layers to set and makes for easier slicing.