Prepare a special baking bag. Clean the lamb and salt it. Brush it with melted butter, in which you've boiled 1 tsp of paprika. Be careful not to burn the paprika.
Place the lamb in the baking bag, pour in a few cups of water, add some spearmint and close the bag.
Roast the lamb on high heat for about an hour. Serve it garnished with boiled peas and potatoes.