Heat the olive oil over medium heat in a large skillet or saucepan. Add the diced pancetta and cook it until it turns crispy.
Add the ground beef to the skillet and cook it until it browns, using a wooden spoon to break it into smaller pieces as it cooks.
Stir in the chopped onion, garlic, carrots, and celery. Let the vegetables cook for approximately 5 minutes until they become tender.
Pour in the red wine and allow it to simmer until it reduces by half.
Add the crushed tomatoes, milk, nutmeg, salt, and pepper. Reduce the heat and simmer for about 2 hours, stirring occasionally. The sauce should thicken and develop a rich flavor.
As the sauce simmers, prepare the pasta following the instructions on the package until it reaches the desired al dente texture. Drain and set aside.
Once the Bolognese sauce is ready, serve it over the cooked pasta. Garnish with grated Parmesan cheese, if desired.