Cut the vegetables for the soup into pieces (tomatoes, onion, carrot, leek, celeriac, ginger).
Clean the herrings, remove dorsal fin and cut them into larger pieces. If you like you can leave the tail fin.
Heat olive oil in pot and sear herring on both sides for about 1 minute. If you didn't remove the tail fins, remove these four pieces and set aside.
Add the anchovy fillets and sear for another minute.
Add all the vegetables, curry powder and cayenne pepper powder and cook for about 3 minutes. Stir well.
Add fish broth and water and cook , reduce heat to low and cook for about 1 hour and stir from time to time.
While the soup is cooking cut the fish filets into bite-sized pieces. Clean the tiger prawns. Set aside.
For Aioli cut the garlic into pieces and add it together with olive oil and egg yolks into your food processor. Mix until smooth and creamy. Salt to taste. Put Aioli into a small bowl and set aside.
Cut french bread into slices and toast until golden brown. Set aside.
After 1 hour cooking take soup from heat and puree soup until smooth. You can do this in your food processor. The soup should be very smooth and creamy. You can sieve the soup to remove all remaining pieces and fish bones.
Put soup on oven over low heat again and add sherry, lime juice, sugar, and saffron. Add salt and pepper to taste.
Add salmon and tilapia pieces, tiger prawns, and the tail pieces of the herrings. Let simmer for about 10 minutes or until fish is done and flakes easily.
Divide the soup into bowls and serve with Aioli and toasted french bread on the side.
NOTE on "small whole fish": I use herrings.
NOTE on fish tails: I don't remove the tail fin and use these pieces for decoration. If you don't like them, remove them. In this case you can leave all herring pieces in the soup.