Steam the fish for 5 minutes or until the fish flakes easily with a fork (or cook in microwave on high 3-4 minutes).
Peel the potatoes and cut into even size pieces. Cook in lightly salted boiling water for 15 minutes or until tender, drain and mash well.
Flake the fish into the pan, discarding any skin and bones.
Add the sweetcorn and chives (if you use them) and beat with a wooden spoon until well combined.
Allow to cool, and when cold enough to handle, shape into 8 fish cakes.
Heat 2 tablespoon of oil in a large frying pan and fry the fish cakes for about 5 minutes each side until crisp, golden and piping hot.
Notes
Freeze the uncooked fish cakes for up to 3 months. Open freeze after shaping and chilling. Wrap well and label. Defrost completely in the refrigerator before frying.