Preheat the oven to fan assisted 200C / 220C / 450 F / gas 8.
Place the salmon fillets on an oven tray and bake for 12-15 minutes until cooked through.
Let the salmon cool before using a fork to flake them into small chunks. Discard the skin and add the flakes into a bowl.
Wash and dry the sweet potatoes, pick them all over with a fork and microwave them on high for 6-8 minutes till cooked.
Allow sweet potatoes cool, split the skin, scoop out the flesh and add to the salmon flakes. Discard the skins.
Add the apple, spring onions, parsley, ground coriander and salt to the sweet potato and salmon and and mix until combined.
Divide into 8 portions, shape into flat patties and dust with corn flour.
Heat 1 tbsp oil in a frying pan and fry half the fishcakes for about 4 minutes on each side until golden and warmed through.
Set aside in a warm place and repeat with the remaining fish cakes. Serve them with a salad and plenty of dips.