Chop finely together the bacon, celery, carrot, and onion. Place 2 oz (60 gm) of the butter and olive oil in a medium size saucepan. When the butter starts foaming add the chopped vegetables, salt, and pepper.
Sauté until onion becomes soft and translucent.
Add the ground beef, ground pork, ground prosciutto, and sausage.
Turn the heat to medium and cook until meat is browned. Stir and break the meat in small bits with a wooden spoon.
Add the wine. Turn the heat to medium-high and let the wine evaporate.
Add the tomato and lower the flame to a very slow simmer. Let the sauce cook very slowly for at least 3 hours. Add a small quantity of broth if the sauce thickens too much.
Stir in the milk (or cream) and 2 oz (60 gm) butter just before removing the saucepan from the heat. Adjust salt and pepper.
In a stockpot bring water to a boil. Add salt (about 1 teaspoon per quart of water).
Drop the pasta in the pot and mix occasionally with a long fork.
Cook until al dente, that is not too soft or overcooked. Taste a little piece form time to time to test for readiness.
Drain thoroughly in a colander. Transfer to a large bowl. Top with the sauce, the parmigiano reggiano cheese, and toss.
Serve accompanied by a small bowl with more grated parmigiano reggiano cheese.