Ingredients
For the lamb
1 leg of lamb, about 2kg/4½lb, hip joint removed (sometimes sold as 'Ezi Carve' lamb)
4 garlic cloves, cut into slices
6 anchovy fillets, quartered
freshly ground black pepper
2 tbsp olive oil
10-12 branches of rosemary
100g/3½oz black olive paste
½ lemon, juice only
For the turnips
2 medium turnips, cut into chunks
8 garlic cloves
salt
freshly ground black pepper
30g/1¼oz butter
1 tsp white wine vinegar
2 tbsp chopped flatleaf parsley

Method
1. Dry the lamb well and hang or rest in a cool, dry spot until its surface is dry to the touch. This makes all the difference to the flavour.
2. Trim off and discard the excess fat. Make incisions all over the meat using a small sharp knife, creating small pockets about knuckle deep.
3. Stuff a garlic sliver and a piece of anchovy into each incision and season the surface well with pepper.
4. Heat half the oil in a flameproof, heavy-duty baking pan and brown the lamb on all sides over a medium-high heat.
5. Allow to cool.
6. Preheat the oven to 200C/400F/Gas 7.
7. Stretch a good length of string along the work surface and overlap the branches of rosemary along the length of the string.
8. Smear the lamb with the olive paste and place it on the rosemary at one end. Roll it up so that it's completely encased in the rosemary and tie the string tightly to secure. It doesn't matter how crudely you do this - as long as the rosemary stays in place.
9. Return the lamb to the baking pan, drizzle with the remaining oil and the lemon juice and place in the oven.
10. Roast for 15 minutes per 500g/1lb2oz, plus 15 minutes more, turning occasionally to cook evenly.
11. Remove from the oven and rest the meat for one-third of the time it took to cook. This ensures a perfectly pink result.
12. Reserve the rosemary for garnish, carve and serve.
13. For the turnips, bring a pan of water to the boil and add the turnips, garlic and half a teaspoon of salt.
14. Simmer gently until the turnips are tender, about 15 minutes. Drain.
15. Add the butter to the pan and heat gently until foaming. Return the turnips and garlic in a single layer and cook over a gentle heat until golden brown, 5-10 minutes.
16. Add the vinegar and parsley and season to taste with salt and freshly ground black pepper.
17. Serve immediately.