Preheat the oven to 220°C (430°F) Gas Mark 7. Place the lamb in a roasting tin.
Mix the mustard, soy sauce, garlic, rosemary and ginger together and then gradually stir in the olive oil to make a paste. Spread this mixture over the lamb.
Put in the oven and roast for 20 minutes, then reduce the heat to 180°C (350°F) Gas Mark 4 and continue to roast for another 50 minutes.
The lamb will be cooked medium at this stage. Remove from the oven, wrap the lamb loosely in foil and allow to rest for 15 minutes before carving.
Roast potatoes and red onions roasted alongside the lamb – peel and quarter potatoes and some red onions and mix with a little olive oil, bay leaves and seasoning. Roast for the last 50 minutes in the roasting tin with the lamb. Steamed vegetables