01 - Season beef chunks thoroughly with salt and pepper.
02 - Heat olive oil in a large skillet over medium-high heat and brown beef on all sides, approximately 2 to 3 minutes per side. Transfer beef to slow cooker.
03 - In the same skillet, add onion, carrots, and celery. Cook until softened, about 5 minutes. Add garlic and cook for an additional minute. Stir in tomato paste and cook for 1 minute.
04 - Transfer vegetable mixture to slow cooker. Add crushed tomatoes, red wine, oregano, basil, bay leaves, crushed red pepper flakes if using, and sugar. Stir well to combine.
05 - Cover and cook on LOW for 8 hours or on HIGH for 4 to 5 hours, until beef is tender and easily shredded.
06 - Remove bay leaves. Shred beef directly in the slow cooker using two forks. Stir in whole milk and adjust seasoning as necessary.
07 - Prepare pappardelle according to package instructions. Drain and distribute evenly onto serving plates.
08 - Ladle beef ragu over pasta. Garnish with freshly grated Parmesan and herbs.