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