1 whole shoulder or leg of lamb, open boned
Oil, for greasing
200ml teriyaki sauce
2 tbsp runny honey
Open the lamb out flat on a board. Score the skin side lightly with a sharp knife and place the lamb into an oiled roasting tin.
Pour over the teriyaki sauce and honey. Turn the lamb in the marinade. Leave for an hour or ideally overnight. If you forget don't worry. It's good with only ½ hour marinating, too.
Heat the oven to 220c/fan210c/gas 7.
Turn the lamb in the marinade again and leave skin side up.
Roast for 25 minutes for rare, 30 minutes for medium rare, 35 minutes for medium.
Remove from the oven and put it on a carving board with a piece of foil and a folded tea towel on top to keep warm. Allow to rest for 20 minutes.
When ready to serve, slice the lamb, adding any juices to those in the roasting pan.
Reheat the juices and transfer to a jug.