Instructions

1. Preheat the oven to 180°C.
2. Wash and pat dry the lamb, then make deep and longish incisions in the meat, using a sharp knife.
3. Cut the vegetables into large chunks, then arrange them in a roasting tin. Pour over the wine.
4. Put the parsley leaves, garlic and butter in a small food processor and whiz until you get a coarse paste. Add the lemon zest and season with salt and pepper.
5. Rub the lamb with the parsley butter, pushing the paste into the cuts with your finger.
6. Place the lamb in the tin, on top of the vegetables.
7. Bake for about 1 hour - allow 40 minutes per kilo plus 20 minutes extra.
8. When the lamb is cooked to your liking, transfer it to a plate, cover with foil and rest for about 15 minutes. Meanwhile, make the gravy: remove the vegetables from the roasting tin, then skim off the fat from the surface. Pour the cooking juice into a saucepan, add the wine and the cornflour, then reduce it to a creamy sauce, while stirring continuously. Gradually add the chicken stock, enough to have a silky, creamy gravy.
9. Carve the lamb and serve it with the gravy and side dishes of your choice.