- Preheat the oven to 210°C. Make slashes 1-2cm deep all over the lamb leg with a sharp-pointed knife.
- In a bowl, mix the crushed garlic with the rosemary, a good grind of black pepper, the olive oil and lemon juice to make a paste.
- Push the paste into the slashes in the lamb leg. Make sure you use all the paste.
- Peel and thinly slice the potatoes and onions. Toss in a bowl with salt and pepper and a little olive oil. Place in the base of a roasting tray in which the lamb can fit so you have a thin layer. Pour the chicken stock on top.
- Place the lamb on the potatoes and pop into the hot oven for 30 minutes. Turn the oven down to 190C for a further 30 minutes. Remove the lamb from the oven and wrap in foil. Allow it to rest for at least 30 minutes. These timings result in pink meat; add another 20 minutes per kg if your leg is larger.
- Serve with a side of green vegetables.
Recipe credits: The Guardian