1. Pat the short ribs dry with paper towels and season generously with salt and pepper. Heat the olive oil over medium-high heat in a heavy-based dutch oven or cast iron pot. Working in batches if necessary, sear the short ribs on all sides to seal the meat and achieve a nice golden crust, about 2 minutes per side. Transfer them to your slow cooker.
2. In the same pot, add another tablespoon of oil and fry the pancetta cubes until crisp, around 3 minutes. Reduce the heat to medium and toss in the chopped onion, celery, carrot and garlic. Gently saute for 5 minutes until veggies are slightly softened and pancetta is cooked through, scraping up any bits stuck to the base of the pan.
3. Reduce the heat to low and add the tomato paste, sauteing for a further minute before sprinkling over the flour. Stir to coat veggies evenly with flour mixture, then pour in the red wine, beef broth, canned crushed tomatoes, bay leaves and dried herbs. Season generously to taste.
4. Next, transfer the vegetable sauce to the slow cooker, pouring it over the top of the seared short ribs. Cover, set the slow cooker temperature on low, and cook for around 6 hours until the meat is fork-tender and falling off the bone (depending on your slow cooker, you may need to add another hour to the total cook time, we recommend taking a peek at the 5½ hour mark to see if it's getting close!)
5. When the ribs are done, transfer them to a chopping board and shred the meat with two forks - it should be juicy, tender and falling off the bone. Discard the bones and return the shredded meat to the slow cooker, stirring to combine with the vegetable ragu. Remove the bay leaves, season to taste, and switch the slow cooker to the keep-warm setting while you cook the pasta.
6. Meanwhile, bring a large pot of salted water to the boil. Cook the pasta to al dente, saving a cup of the starchy cooking water before draining.
7. Drain the cooked pasta and immediately combine with the braised short rib ragu, stirring gently with a few spoons of the pasta cooking water to distribute the rich, meaty sauce through the pasta.
8. Serve immediately, topped with extra parmesan and chopped parsley for a decadent and delicious pasta dish sure to impress.