The fish in this soup is as important as the broth in which it is served. This is an interesting exercise in both making stock and cooking different types of fish. In fact chicken stock is preferable to fish stock as once the fish cooks in the stock it will taste fishy. Chicken stock is also better because it has more body.
The fish should be in fillets. The idea is that everything in the bowl should be eatable and not be a contest between the food and your fingers to see whether hunger can be assuaged before shirt and trousers are irreparably stained.
The dish appears deceptively simple but calls for much care to be successful. The stock must be well chosen fresh and in top condition; the use of cream must be carried out with restraint; each piece of fish with its differing texture must still end up perfectly cooked; the creaminess must be balanced by just the right amount of sharpness; the croûtons and chopped parsley should lift the soup and add another dimension to its textures not just look pretty.
The finished soup should taste fresh and natural. It is based on the same principle as a poached fish dish with sauce but the larger volume of liquid allows you scope for more delicacy.
Points to watch
Do not taste with your finger or a teaspoon - use a soupspoon. Remember when seasoning that the dish will be consumed by the bowlful not by the teaspoonful like sauce.
The soup must be served and eaten as soon as it is made or the pieces of fish will overcook spoiling the point of the dish. It does not reheat successfully anyway.
The fish listed as ingredients are just a guideline. Use whatever is best. Do try though to introduce a variety of fish types both white fish and shellfish as this diversity is part of the dish's appeal.
1 litre stock
2 shallots chopped
150g red mullet filleted
75g haddock fillet
2 fillets from a 450g Dover sole
75g shell-on prawns
1tbs lemon juice
Salt and pepper
1 egg yolk
1tbs double cream
2 tomatoes skinned and diced
1tbs chopped parsley
1 slice white bread for croûtons
Heat the stock and chopped shallots. Cut the fish into large cubes - about 12mm. Turn the fish in lemon juice and season lightly with salt and pepper. When the stock reaches the boil add the fish in the order of which fish takes longest to cook. So in my ingredient list the haddock would be first followed about a minute later by the sole and red mullet then at the last moment the scallops and prawns. The whole cooking process would take about five minutes depending on how thick the pieces were cut.
Mix the egg yolk and cream together with a tablespoon of the stock. Turn off the heat and stir in this mixture. The soup may now be kept warm but not reboiled. Add the tomato and parsley. Fry the croûtons and sprinkle over. Finally and importantly taste the soup and alter the seasoning and acidity if need be. The difference between a bowlful of boiled milky fish and a delicate elegant soup lies in the care and judgement with which this is done.