01 - Heat olive oil in a large skillet over medium heat. Add pancetta, onion, carrots, and celery. Cook for 5 to 7 minutes until softened.
02 - Stir in minced garlic and cook for 1 minute until fragrant.
03 - Add ground beef (and pork if using), breaking it apart with a spoon. Cook until no longer pink, about 5 minutes.
04 - Move the cooked mixture into the slow cooker.
05 - Add crushed tomatoes, tomato paste, red wine, broth, oregano, basil, bay leaf, red pepper flakes, salt, and black pepper. Stir thoroughly to combine.
06 - Cover and cook on LOW for 6 to 8 hours or on HIGH for 3 to 4 hours until sauce thickens and flavors meld.
07 - Remove bay leaf and adjust salt and pepper to taste.
08 - Serve sauce hot over pasta, garnished with chopped fresh parsley or basil.