500g sweet potatoes, peeled and cut into thick slices
200ml red wine
200ml beef stock
1 tbsp sweet potato flour mixed with 2 tbsp water
Make 10 small cuts on the leg of lamb and place lamb in a roasting pan.
Cut prosciutto in half lengthways and roll 1 basil leaf and 1 slice garlic tightly in each slice of prosciutto. Press one prosciutto roll into each cut on the lamb.
Lightly brush olive oil over the lamb and sprinkle with salt and pepper. Roast the lamb in a preheated oven at 210°C for about 15 minutes.
Toss both potatoes with 2 tablespoons olive oil and a teaspoon each of salt and pepper in a mixing bowl. Arrange potatoes around the lamb, then reduce the oven temperature to 180°C and continue to roast for 40 minutes.
Turn the vegetables during roasting so they brown all over. Roast until lamb is cooked to your preferred tenderness.
Remove lamb to a large serving plate and cover loosely with tin foil. Transfer the potatoes to a baking tray. Drizzle over with a little extra olive oil and roast for a further 8-10 minutes or until golden and crisp.
Drain off excess fat from the roasting pan. Add wine and stock to the pan and bring to the boil over medium heat. Stir with a ladle to loosen and dissolve the baked residue (drippings) from the base of pan.
Simmer for 3-4 minutes or until stock is reduced. Add thickening to the gravy and serve with the lamb and potatoes.