Fish Stew with Rouille

1. Twist the heads off the prawns, peel away the legs and shells (leaving the tails on) and devein each one. Fry the shells in 1 tbsp oil for 5 minutes until dark pink and golden in patches, add the wine and boil it down by two thirds, then pour in the stock and strain into a jug, discarding the shells.
2. Heat the rest of the oil in a deep frying pan or casserole, add the fennel, onion and garlic, season, cover and cook gently for 10 minutes until softened. Meanwhile, peel and cut the potato into 2cm chunks, put them in cold water, bring to the boil and cook for 5 minutes until almost tender, then drain.
3. Peel a strip of orange zest and add it to the pan with the star anise, bay and 1/2 tsp harissa. Fry gently, uncovered, for 5 to 10 minutes until the vegetables are soft, sweet and golden.
4. Stir in the tomato puree and cook for 2 minutes, then add the tomatoes and the strained stock. Simmer for 10 minutes until slightly thickened and season to taste. The sauce can be made ahead at this point. Scrub the mussels and pull off any beards, throwing out any that won't close when tapped.
5. Reheat the sauce if needed, then gently stir in the potato, fish chunks and prawns. Bring back to the boil, cover and simmer for 3 minutes. Scatter the mussels over, cover and cook for 2 minutes more until the shells open wide, discarding any that stay shut. Scatter over the thyme leaves.
6. For the quick rouille, stir the rest of the harissa through the mayonnaise. Serve the stew topped with spoonfuls of rouille, with good bread for soaking up the juices.

Tips from the ZestyPlate Kitchen

• Hold on to the prawn shells. Frying them and simmering them in wine gives you an intensely savoury stock.
• Add the seafood in stages according to how long each takes, with the mussels going in last.
• Throw out any mussels that stay open before cooking, and any that stay shut after.
• The orange zest and star anise are quiet but vital, lending the broth its unmistakable Provencal scent.