Preheat the oven to 160°C.
Heat the oil in a large heavy-based ovenproof casserole dish and, in batches, sear the beef cheeks on all sides for a few minutes. Remove to a dish and set aside.
Add the pancetta to the dish and cook over a medium high heat for 3-4 minutes, then reduce the heat and add the onion, celery, garlic, rosemary and oregano. Cook for 10 minutes until the onion is softened but not coloured. Add the tomato paste, wine, passata and sugar and stir to combine. Season to taste and bring to a boil.
Add the beef cheeks back to the dish, cover and braise in the oven for about 4 hours until meltingly tender. Remove and shred the beef cheeks and add back to the sauce.
To serve: Serve the ragù over hot pappardelle and top with parmesan and fresh oregano.