This John Dory curry is a bit out of the ordinary. By cooking down the sauce to an intense paste then smearing it over the fillet,it looks amazing and tastes incredible. The mix of coriander,crispy shallot and lime leaf tops it all off. If you can't find John Dory,substitute it for flathead or whiting. If it's a thicker fillet,slice it in half so it cooks quickly under the grill.