01 - Pat the lamb pieces dry with paper towels. Season with salt and pepper.
02 - Heat olive oil in a large Dutch oven or heavy pot over medium-high heat. Brown the lamb in batches, ensuring all sides are seared. Transfer browned lamb to a plate.
03 - In the same pot, add onion, carrots, and celery. Cook for 6–8 minutes until softened, stirring occasionally. Add garlic and cook for 1 minute more.
04 - Return the lamb to the pot. Add rosemary, thyme, and bay leaf. Pour in the red wine, scraping up any browned bits from the bottom. Simmer for 2–3 minutes.
05 - Add crushed tomatoes and broth. Stir well and bring to a gentle simmer.
06 - Reduce heat to low, cover, and cook for 2½ to 3 hours, stirring occasionally, until the lamb is very tender and the sauce has thickened. Remove herbs and shred lamb into the sauce using two forks. Adjust seasoning if needed.
07 - About 20 minutes before the ragu is ready, cook the pappardelle in a large pot of salted boiling water according to package instructions until al dente. Drain, reserving some pasta water.
08 - Toss the pappardelle with the lamb ragu, adding reserved pasta water if needed to loosen the sauce. Serve hot, topped with grated Parmigiano-Reggiano and fresh parsley if desired.