Fish soup with aioli sauce

INGREDIENTS

• 2 free-range egg yolks
• 3 garlic
• pinch salt
• 250g/9oz olive oil
• ¼ lemon
• pinch cayenne pepper
• 100ml/3½fl oz olive oil
• 1 large Spanish onion
• 1 bulb fennel
• 1 stick celery
• 1 carrot
• 5 garlic
• 2 sprigs fresh thyme
• 1 fresh bay leaf
• pinch saffron
• 500g/1lb 2oz gurnard
• 500g/1lb 2oz grey mullet
• 300g/10½oz tomatoes, seeds
• 300ml/10½fl oz dry white wine
• 1.2 litres/2 pints cold water
• 4 pinches coarse sea salt
• 3 pinches cayenne pepper
• 1 tbsp Pastis
• 30 toasted croutons
• 100g/3½oz Gruyère