A mouthwatering roast leg of lamb with a fresh and fragrant mint and pesto sauce.Using the point of a sharp knife make small incisions all over the lamb, then poke a slice of garlic into each hole. Cut the rosemary into smaller sprigs and push them into the incisions too. Cover and chill for at least 2 hours, preferably overnight.Take the lamb out of the fridge 1hr before roasting to allow to come to room temperature. Heat oven togas 7, 220°C, fan 200°C. Place the chopped onion and carrot in a large roasting tin, then sit the lamb on top, season well and drizzle over the oil. Roast for 15 mins, then turn down to gas 5, 190°C, fan 170°Cand roast for a further 1hr 20 mins. Remove the lamb, cover lightly with foil and leave to rest in a warm place for 30-45 mins. (Now’s the time to pop your potatoes in the oven).Meanwhile make the pesto sauce. Boil the kettle and pour over the peas, leave to stand for 1-2 mins. Drain the peas, then run under cold water. Once cool transfer to the small bowl of a food processor. Add the remaining ingredients and blend to a smooth paste. Season and transfer to a serving dish.Strain any lamb juices from the roasting tray into a small saucepan. Add any resting juices and heat through. Slice the lamb and serve with the roasting juices and pea and mint sauce.See more Lamb recipes For top tips on protecting you and your family when preparing raw meat and poultry, visit Food Safety in the Home.