Seafood minestrone

Fillet the fish, cut into cubes and set aside.
Place fish carcass in a large saucepan and cover with 2 litres water. Add chopped onion, parsley sprigs and lemon rind. Bring to the boil, reduce heat and simmer for 10 minutes. Remove from heat and strain.
Heat olive oil in a large saucepan. Add leeks, carrots and garlic and sauté over low heat for 5 minutes. Add strained stock, tomatoes and wine and bring to the boil. Add pasta, broken into 5 cm pieces, and cook for 5 minutes. Add fish, reduce heat and simmer for a further 5 minutes. Stir in lemon juice and season with salt and freshly ground black pepper. Serve immediately with Italian bread or crostini. Serves 4-6.