Dice the bacon and finely chop the celery, carrots, and onion;
Brown the bacon in a stockpot or cast iron pot with 4 tablespoons of oil; add the vegetables and season with plenty of salt to release the liquid;
Fry over medium heat until softened and golden brown; make sure the water has evaporated because a too liquid ragù does not taste good;
Stir in all the ground meat, breaking up all the clumps of meat and brown over medium-high heat. The mix should be smooth, golden brown, and dry. Be careful not to burn it;
Pour in the wine, combine well, and boil off the alcohol;
Season with salt;
Add the tomato sauce or the peeled plum tomatoes with their liquid, cover with a tight-fitting lid but leave enough space to let the steam out. Reduce the heat to low, and let cook for about 2 hours;
Stir in some broth if the sauce gets too thick;
Season with salt and pepper; after about 2 hours, pour in the milk for a creamy smooth sauce.