Dice salmon and haddock into approx 1 cm cubes. Pan-fry in hot oil until lightly golden and slightly cooked for approx 2 minutes and then drain.
Quickly sauté prawns in hot oil, drain and reserve.
Add cooked fish and prawns to mashed potato, chop the basil and add along with one beaten egg and the chopped spring onion and Orkney cheese.
Divide into 4 or 8 pieces, mould into balls. Flatten slightly and neaten into round shapes using a palette knife.
Flour all sides, dusting off any excess flour. Coat in a beaten egg, removing any excess egg. Gently cover with breadcrumbs.
Pan-fry in oil in a non-stick pan until golden on both sides.
Serve with a tomato sauce and perhaps a little salad on top of fish cake.