Step 1: Heat 2 tablespoons of olive oil in a large skillet over medium heat. Add finely chopped onions, carrots, and celery, sautéing for 8-10 minutes until the vegetables are translucent and fragrant.

Step 2: Increase the heat to medium-high and add 1 pound of ground beef and 1 pound of ground pork to the skillet. Cook for about 10-12 minutes, stirring occasionally until the meat is deeply browned and crumbled.

Step 3: Reduce the heat to medium, adding 3 cloves of minced garlic to the skillet and stirring for about 1 minute until aromatic. Pour in 1 cup of dry red wine, scraping the browned bits from the bottom of the pan.

Step 4: Stir in 2 cans of crushed tomatoes, 1 cup of beef stock, and 1 cup of whole milk into the skillet. Season with 1 teaspoon of dried oregano, salt, and pepper to taste, and bring this mixture to a low boil.

Step 5: Lower the heat to a gentle simmer, leaving the ragu uncovered for 2 hours. Stir every 30 minutes to prevent sticking.

Step 6: In a separate saucepan, melt 4 tablespoons of unsalted butter over medium heat. Add ¼ cup of all-purpose flour and whisk to form a roux, cooking for about 2-3 minutes until lightly golden.

Step 7: Gradually whisk in 2 cups of warmed whole milk, continuing until the sauce thickens, and finally, season with a pinch of nutmeg and salt.

Step 8: Preheat your oven to 190°C (375°F). In a baking dish, start layering by spreading a thin layer of the ragu on the bottom. Follow with lasagna noodles, a layer of ricotta mixed with one egg, a smooth Béchamel layer, and shredded mozzarella.

Step 9: Cover the lasagna with foil and bake in the preheated oven for 30 minutes. Afterwards, remove the foil and bake for an additional 15 minutes until the top is golden brown and bubbling.

Step 10: Once baked, allow the lasagna to rest for 20 minutes before slicing.