Heat a large dutch oven or heavy saucepan over medium-high heat, and add 1 tablespoon of the oil.  When hot, add the ground beef, ground pork, pancetta and chopped mushrooms.  Season with salt and pepper.  Brown, breaking up the meat and cooking until the mushrooms are cooked and the meat is no longer pink.  Transfer the meat to a separate bowl and drain the grease from the pan.

To make the soffritto, reduce the heat to medium and add the remaining tablespoon of olive oil to the dutch oven.  Add the onion, carrots, and celery and mix together, cooking until the vegetables are soft begin to caramelize, about 10-15 minutes.  

Add the garlic to the vegetables and cook for another 1-2 minutes.

Add the wine to the soffritto and cook for 3 minutes, scraping the bottom of the pan, until slightly reduced.

Return the browned mushrooms and meat to the pan, then add in the crushed tomatoes, tomatoe puree, milk, bay leaves and thyme.  Stir to combine, then bring to a simmer.  Reduce meat to low and partially cover the dutch oven with a lid.  Simmer for 4 hours, stirring frequently.  

When the sauce has thickened, remove the bay leaves and thyme sprigs, then taste and adjust seasoning, adding more salt if needed.  

When the sauce is ready, bring a large pot of water to a boil and season generously with salt.  Add the fresh pasta and cook for just 2–3 minutes. Drain the pasta, then return to the pan and toss with however much bolognese sauce you would like.  Remaining sauce freezes and reheats well and can be used in lasagna bolognese.  Garnished with chopped Italian parsley and Parmesan cheese.