Heat a little oil in a heavy-bottomed pan and gently saute rosemary, chilli, fennel, red onion and 1 garlic clove until reasonably tender, stirring now and again.
Add diced tomatoes, soaked saffron with liquid, 1 tbsp parsley, 1 cup stock, sherry vinegar and seasonings. Stir and cook down a little, adding more stock if needed.
Then add the mussels and fish. Cover, turn heat down a little and gently cook until fish is ready (and opaque in the centre), turning once. Remove mussels as they open and discard any that don’t.
To make the aioli, combine mayonnaise, lemon juice, mustard and remaining garlic. Taste for seasoning.
To serve, spoon a decent amount of the sauce and vegies into individual bowls. Arrange mussels around the edge and place fish in the centre with a good dollop of aioli and a sprinkling of parsley on top.
