2) Heat 2 1/2 tablespoons of the olive oil in a large pan. Add the onion, garlic, fennel and carrot and gently cook for ten minutes. Add the tomato puree, star anise, saffron and cayenne pepper and cook for two to three minutes. Add the white wine and Pernod, bring to the boil.
3) Heat the rest of the olive oil in a frying pan. Season the chunks of fish and cook for two minutes until caramelised. Add to the soup along with the mussels. Simmer for five minutes or until the mussels open (discard any that stay closed).
4) Serve in bowls with a dollop of garlic mayonnaise in each and scattered with grated Gruyere cheese. Provide crusty bread to mop up the juices.
Variation: Try making this soup without the tomato juice. You'll be left with a delicious Mediterranean sauce for fish like sea bass or red mullet. It's also fantastic with scallops.