Seafood

Twist prawns' heads off, peel shells leaving tails intact and devein prawns
Fry prawn shells in 1 tbsp oil until dark pink and golden in patches
Add wine, boil down by two thirds, pour in stock, then strain into a jug and discard shells
Heat remaining oil, add fennel, onion and garlic, season, cover and gently cook until softened
Peel and cut potato into chunks, boil in cold water until almost tender, then drain
Add orange zest, star anise, bay leaf and ½ tsp harissa to the vegetables and fry uncovered until soft and golden
Stir in tomato purée, add chopped tomatoes and simmer until the sauce thickens slightly
Scrub mussels and remove beards, discard any that remain open after tapping
Reheat sauce if needed, gently stir in the drained potatoes, white fish chunks and prawns, bring to the boil and simmer 3 minutes
Scatter mussels over the stew, cover and cook until shells open, discard any that remain closed, then scatter with thyme leaves
Make quick rouille by stirring the remaining harissa into mayonnaise
Serve the stew in bowls topped with spoonfuls of rouille and serve with bread