1. Pre‐heat oven to 180°C. Mix the olive oil, thyme, zest and lemon juice. Season and spoon half the mixture over the lamb and toss the other half through the vegetables.
2. Place lamb into a roasting dish and bake for 15 minutes before adding the tossed vegetables and cooking for a further hour. Add the asparagus and cook a further 5 minutes
3. Rest the meat under foil in a warm place.
To serve, slice the lamb and serve with the vegetables, scattered with fresh thyme leaves and lemon zest.