step 1
Preheat the oven to180c or gas mark 4
step 2
To butterfly the leg of lam place the boned leg skin side down on a chopping board. Locate with your fingers the cavity where the bone was and carefully place the sharp knife into the leg cavity blade side upwards and carefully cut upwards so the leg opens up into two joined halves. Tern the leg over skin side up, cover with cling film and beat with a rolling pin so the leg becomes flat and even.
step 3
Peal and grate the ginger and garlic Mix together the five spice, grated ginger, garlic with a little soy sauce so the consistency resembles tomato pure.
step 4
Score the skin with a sharp knife making sure not to cut to deeply. (Tip a Stanley knife with a new blade dose the job to perfection) Place the lamb into a roasting tin with deep sides
step 5
Rub the five spice paste into the scores in the skin of the lamb Pour over the black bean sauce coating the lamb. Sprinkle evenly the Muscovado sugar over the lamb.. Cover with tinfoil and place in the oven on the middle shelf for 1 & quarter hours
step 6
remove the tinfoil and cook on the top shelf for a further 15-min.