01 - Season the beef chunks generously with salt and pepper.
02 - In a large skillet over medium-high heat, heat olive oil. Sear the beef on all sides until browned (about 2-3 minutes per side). Transfer to the slow cooker.
03 - In the same skillet, add onion, carrots, and celery. Cook for 4-5 minutes until softened. Stir in garlic and tomato paste; cook for 1 minute more.
04 - Transfer the vegetables to the slow cooker. Add crushed tomatoes, red wine, beef broth, oregano, thyme, bay leaves, and red pepper flakes. Stir to combine.
05 - Cover and cook on low for 8 hours or until the beef is very tender and shreds easily. Discard bay leaves.
06 - Shred the beef in the slow cooker using two forks, then stir to mix with the sauce. Taste and adjust seasoning with salt and pepper if needed.
07 - About 20 minutes before serving, cook the pappardelle according to package instructions. Drain, reserving 1/2 cup of pasta water.
08 - Toss the cooked pappardelle with the beef ragu, adding a splash of pasta water as needed to coat. Serve hot, sprinkled with Parmesan and fresh parsley.