French
Sauté the chopped onion, sliced fennel, leek and garlic in olive oil until soft.
Add the tomatoes, saffron, orange zest, bay leaf and thyme and cook 5 minutes.
Pour in the fish stock, bring to a boil and simmer 20 minutes to build a rich, aromatic broth; season well.
Add the firmest fish first and poach 5 minutes, then add the more delicate fish and the shrimp.
Add the mussels, cover and cook 4 to 5 minutes until they open and the fish is just cooked through.
Discard any unopened mussels and check the seasoning.
Serve the broth and seafood in wide bowls with toasted baguette spread with rouille.