Season the ribs. Preheat oven to 350°F / 175°C. Pat ribs dry with a paper towel, then generously season on all sides with 1 Tbsp Kosher salt and ½ tsp freshly ground black pepper.
Sear the ribs. Preheat a large dutch oven over high heat, then add a few tablespoons of a light, neutral oil. When very hot, work in batches as needed to sear the ribs until browned on all sides, about 10-12 minutes total. Transfer seared ribs to a plate, then reduce heat to medium-high.
Sauté the vegetables. Drain off all but 2 Tbsp of fat from the pan, then add diced onion, carrots, celery, and garlic, then cook, stirring occasionally, until translucent—about 4-6 minutes.
Stir in tomatoes. Stir in 2 Tbsp tomato paste until dissolved, then deglaze with 2 cups (475ml) red wine, being sure to scrape the bottom of the pan. Allow this to cook down for 1-2 minutes, then add a 28oz can of whole tomatoes, either crushing them with your hands directly into the pot or breaking them up with the back of a wooden spoon. Add 2 cups (475ml) low-sodium beef stock and 2 Tbsp (30ml) balsamic vinegar, then stir and bring to a boil.
Cook the ribs. Using kitchen twine, tie together rosemary (or thyme) and sage, then place in the pot with 2 bay leaves and a Parmesan rind. Return the beef to the pot, cover with a lid, then transfer to a the oven. Cook until tender and falling off the bone, about 2½–3 hours.
Shred the beef. Transfer the beef ribs to a large bowl. Cool until you're able to handle, then discard the beef bones. Use your hands or two forks to shred the beef.
Discard herbs and Parmesan rind. Remove the herbs and Parmesan rind, then return the shredded beef to the sauce. Stir well.
Cook the pasta. To serve, cook pappardelle until al dente according to package directions, then drain, reserving at least 1 cup of the pasta cooking liquid.
Finish, then serve! If serving all the ragu at once, toss the cooked pappardelle directly with the sauce until evenly coated. If using only a portion, heat 1–2 cups of ragu in a large skillet over medium-high heat. Add the cooked pasta and a generous splash (about ¼ cup) of reserved pasta water, tossing until glossy and well coated. Finish with shaved or grated Parmigiano Reggiano, chopped parsley, and a pinch of flaky sea salt before serving.