Method
1. Remove the lamb from the fridge an hour before cooking.
2. Heat the oven to 200c.
3. Roughly chop half the rosemary, zest the lemon. Mix together with 3 cloves of garlic and 2 tbsp olive oil. Rub all over the leg. Season with salt and pepper.
4. Place the lamb in a large roasting tin. Roast the leg for 1 ¼ hours if you like it pink, 1 ½ if you like it well done. Remove from the oven and let rest for 15 minutes.
5. While the leg is roasting prepare the potatoes. Boil the potatoes for 10 minutes. Drain and allow to steam. Slice and layer, overlapping slightly, in the bottom of a lightly greased ovenproof dish, scatter the remaining garlic and rosemary through the potatoes as you layer them. Drizzle with olive oil, season with salt, cover and roast in the shelf underneath the lamb for 35 minutes and then a further 10-15 with the cover off until golden.
6. For the salsa verde, remove all the stalks from the herbs and chop roughly. Add the rest of the ingredients and mix together. Taste and season if necessary.
7. Carve and serve with the potatoes, seasonal greens and salsa verde.