4 garlic cloves, finely chopped
400g/14oz rhubarb, thinly sliced
2 large sprigs rosemary, leaves removed from stalks and finely chopped
1 tsp chilli powder
2 tbsp honey
oil, for coating
2 tbsp salt
50驳/1戮辞锄 butter
whole leg of lamb, about 1kg/2lb 4oz butterflied (ask a butcher to do this)