Cut the fish fillets into chunks; place in a food processor. Add the breadcrumbs, chives or spring onion. Season and process until the fish is chopped, but still with some texture.

Dived the fish mixture into about 16 even-sized pieces, then mould them into balls with your hands.

Place the tomatoes and mushrooms in a saucepan; cook over a medium heat until boiling. Add the fish balls, cover and simmer for about 10 minutes until cooked. Serve hot.