This pasta-clinging ragu doesn't ask a lot from you, but gives so much in return. Allow just a little time and the dividends are doubly paid in saucy, rich bowls with a flavour so knock-'em-dead that you'll want to open the kitchen window to drive your neighbours mad with the aroma of it.
Heat oil in a large heavy based saucepan over medium-high heat. Season lamb shanks with salt and pepper, add to pan and cook, in batches if necessary, for 6–8 minutes or until browned on all sides. Remove from pan. While lamb is browning, continue with step 2.
Peel and finely chop onion. Peel and thinly slice garlic. Pick rosemary leaves from their stems.
Reduce heat to medium, add onion, fennel seeds, garlic and rosemary to pan and season. Cook for 3–4 minutes or until onion has softened. Add tomato paste and cook for 30 seconds. Return lamb shanks to pan with tomatoes and 200ml water and bring to a simmer. Reduce heat to low, cover with a lid, and cook for 2½ hours or until lamb is falling off the bone.
Remove kale leaves from stems, discarding stems. Tear leaves into bite-sized pieces.
Cook spaghetti in a saucepan of salted, boiling water for 9 minutes or until al dente. Drain well.
Once lamb is tender, use tongs to shred meat, discarding bones. Add kale and spaghetti to pan and cook for 2–3 minutes or until kale has wilted. Season to taste. Divide spaghetti between bowls and top with parmesan to serve. Serve with salad leaves drizzled with your favourite dressing.