1. Add onion, celery, carrots, garlic and mushrooms to the food processor. Hit the pulse but a few times until all ingredients are ground up fine.
2. In a dutch oven pan add butter and olive oil and sauté the vegetables mixtures for about 10 minutes on medium heat adding salt and pepper to taste.
3. Slide the vegetable mixture aside on the pan and add the pancetta ground pork and ground beef and brown the meats for about 10 minutes. While meat is browning incorporate the vegetables into the meat. If your meats are fatty and there is excess oil, remove at this time.
4. Stir in the tomato paste until incorporated then add the wine and milk and fresh thyme. Cover place the lid on the Dutch oven and cook on a simmer low temp for 90 minutes . Keep stirring the sauce so it does not stick to the bottom of the pan.
5. Before serving garnish the sauce with fresh basil and serve with you favorite wide noodle like tagliatelle pasta, and 2 year aged parmesan.