Heat heavy pot over medium heat. Add olive oil and heat. When hot, add onions, celery, and carrots and saute until soft, about 8-10 minutes. Add
Add beef, pork, and pancetta; saute, breaking it up with the back of a wooden spoon, until browned, about 15 minutes. Add
Add wine and boil for 2 minutes, stirring often and scraping up browned bits. Add 2 12 cups stock and tomato paste: stir to blend. Reduce heat to very low and gently simmer, stirring occasionally, until flavors meld, about 1 1/2 hours. Season with salt and pepper.
Warm milk so it does not curdle when added. Gradually add to the sauce. Cover with lid partly ajar and simmer over low heat stirring occassionally, until milk is absorbed, about 45 minutes, adding more broth to thin if necessary. Do not overthin.
Cook pasta in salted water until al dente and drain. Transfer pasta into the sauce and toss to coat. Divide onto warm plates and serve with Parmesan cheese. Enjoy!