Scale the red mullet and sea bass, and scale and skin the Dover sole; the John Dory and monkfish tail should also be skinned. Shell the Dublin Bay prawns and save the shells and heads. Fillet all the fish and trim each of the fillets, saving the trimmings. Cut the fillets into pieces to get 16 from each fish. Roughly chop up the fish bones, including the heads, and the shells and heads of the prawns together with the trimmings. Wash everything well, then drain.
Heat the oil in a large pan and when hot add the vegetables and garlic. Cover and gently sweat, without colouring, until they start to soften. Add the fish bones, heads and trimmings, and the shells and the heads of the prawns and continue sweating for about 2 minutes, again without colouring. Sprinkle the flour over the top of the bones and place the pan into the oven for about 5 minutes. Turn the
After 30 minutes strain the soup through a strainer, pressing the bones dry, then strain again through muslin into a clean pan. Return this to the heat and bring back to the boil. When boiling, add the cream, bring back to the boil again and allow to reduce slightly. Remove from the heat and allow to go cold.