In a medium heavy-bottomed pot, heat butter and olive oil over medium heat until butter begins to froth. Add onion, celery, carrot, garlic, and bacon. Cook until onions are translucent, about 8 to 10 minutes.
Remove bacon and skim out most fat. Chop lean portions of bacon in small pieces and return to pot. Add ground sausage and cook until sausage is browned, breaking up.
Raise heat and add wine and beef broth. Cook sauce until wine and consomme are mostly evaporated, or at least reduced by half. Turn heat down to simmer and add oregano, salt, pepper, sage, red pepper flakes, and nutmeg. Let cook for approximately 20 minutes.
Add crushed tomatoes and bring heat to a boil, then reduce heat and simmer very slowly, partially covered, for about 2 to 4 hours, stirring occasionally to prevent sticking. The longer the better!
About 5 to 10 minutes before serving, add milk. Combine freshly cooked pasta and sauce over very low heat and allow pasta to soak up the sauce, a few minutes.
Notes
Combine pasta and sauce over very low heat and allow to soak up the sauce for a few minutes.