Mediterranean flavours are the highlight of this sumptuou seafood stew.
Chop the full-flavoured and delicate fish into large, bite-sized pieces. and refrigerate (keeping the full-flavoured fish separate from the delicate). Put the rinsed fish heads and bones in a large soup pot, pour the water over, bring to a boil, and simmer twenty minutes. Strain, reserving the liquid.
Heat the oil in the same pot and fry the onions, leeks, and fennel until soft, 10 minutes. Add the tomatoes, garlic, bouquet garni, fennel seed, orange peel, and saffron. Season with salt and pepper. Pour over the fish stock, and simmer half an hour. Remove the bouquet garni and the orange peel.
Bring the liquid to a rolling boil. Add the full-flavoured fish and cook 5 minutes. Add the delicate fish and the splash of Pernod and continue cooking until all the fish is tender, 5 minutes longer.
Ladle into warm soup plates, sprinkle irreverently with parsley if you like, and top with a rouille-smeared croûte.