Heat half the oil in over medium/high heat in a large stove-top and oven-proof casserole dish. Brown the shanks all over then set-aside
Add remaining oil to the pan and add onion, cook for 3-4 minutes. Stir in passata and stock and bring to a simmer. Return the lamb shanks back to the casserole dish and cover with lid and slow cook in the oven for approximately 3 hours or until the meat is falling off the bone
Remove the shanks from the pan and shred the lamb with two forks. Return to casserole dish to warm through. Season with salt and pepper and stir in butter and grated Parmesan. Keep warm
Meanwhile, cook the pasta in a large saucepan according to packet instructions. Drain well
Add pasta to ragu and stir through to coat. Transfer to a serving dish and sprinkle with shaved Parmesan
Tips & Hints
This dish is ideal to make ahead. Reheat in slow cooker on low before adding pasta.
You can also cook this recipe in a slow cooker. Be sure to sear the shanks and cook the onion before adding to the slow cooker to enhance the flavour.