Chop the beef with a knife or meat grinder.
Chop pancetta or pork finely with a knife or mezzaluna/herb chopper.
Finely chop carrots, celery, and onions.
Heat a pan and fry the pancetta.
Add oil and butter and let it melt.
Add carrots, celery, and onions, stir and let fry on low heat for 5 minutes.
Turn up the heat, add the beef and brown it - it should fry, not boil.
Add the wine a little at a time and let it evaporate.
Now add the tomatoes, stir, and let it simmer for 2 hours. Add stock as needed when it gets too thick.
Add the milk, stir it well into the ragú and let it simmer for another 10 minutes. Then season with salt and pepper.
Bring water and salt to a boil in a large pot. If you don't have a 5-liter pot, use a 3-liter one. That works too!
Add the pasta and cook it until almost done.
Transfer the pasta into the pan with the ragú without draining it too much - the pasta water helps to 'bind' the sauce and get it to stick to the pasta.
Quickly bring the dish to a boil and serve in deep plates with parmesan cheese on top.