Thinly dice the onion and mince the coriander.
Mix the onion and coriander with raspberries and blackberries. Set aside.
Cook the fish in a hot pan with some oil. First the skin side for 4-5 minutes, then the other side for 4-5 more minutes.
Season the fish with salt and pepper to taste.
Season the raspberry and blackberry sauce with lemon juice and salt to taste, and mix gently.
For the assembly:
Pour a spoonful of sauce on one side of the plate, then place the fish on top of the berries. This will add height to the assembly. Finally, add some more berries on top of the fish.
