Photo: Martin Poole
Preheat the oven to 180°C/fan 160°C/gas mark 4. Toast the pine nuts in a frying pan until golden, then set aside. Fry the onion in the olive oil for 8 minutes until softened and golden.
Meanwhile, wilt the spinach in a large lidded pan. Tip into a colander and press out the excess moisture.
Unroll the lamb on a chopping board, fat-side down, and season lightly. Mix together the pine nuts, onion, spinach, cinnamon, cumin and raisins and cook for 1-2 minutes. Spoon evenly across the lamb, then re-roll and tie to secure. Place the lamb joint in a roasting tin and roast for 25 minutes per 500g plus 25 minutes for medium well or 20 minutes per 500g plus 20 minutes if you prefer it pink, basting occasionally. Rest for 10-15 minutes before carving.