Chop the onion, carrot, and celery into 1/-4-inch dice or process until finely chopped.

Arrange the bacon in a large, heavy pot and cook over medium heat for 5 to 7 minutes or until most of the fat is rendered. Add the diced vegetables and cook over low heat until the vegetables are softened and the onion is translucent.

Add the ground beef and pork to the pot and break it up into small pieces. Cook, stirring frequently, until the meat is no longer pink. Add the wine and bring to a simmer, scraping up any browned bits in the bottom of the pan. Continue cooking for a few minutes or until the wine has almost all evaporated. Add the tomato paste, crushed tomatoes, beef stock, and bay leaf. Bring to a simmer.

Cover the pot, reduce the heat to low, and simmer for 1 1/2 hours. If the sauce is thin, continue cooking, uncovered, for 30 minutes more or until thickened. Add the milk and cook for another few minutes, or until hot.

Taste and season with salt and pepper, as needed.

Remove the bay leaves and serve with hot cooked pasta. Pass the Parmigiano Reggiano and enjoy!

Refrigerate leftovers in an airtight container and enjoy within 4 days. Alternatively, freeze the sauce for up to 3 months. Defrost in the fridge overnight and reheat on the stovetop or in the microwave.