Part of the butter mixed with parsley, chopped capers, grated lemon peel, pepper and the resulting mixture is thoroughly cleaned mackerel. Spread with melted butter parchment sheets (or fthe oil) and on each pile a mackerel. Mackerel are wrapped well. Place on BBQ in a hot oven and bake 25-30 minutes. Mackerel are removed, placed on warmed plates, pour the juice of parchment and decorate with slices of lemon.