Method:
1. Bake the potatoes at 200˚C (180 fan), gas mark 6 for about 45 minutes until cooked. Leave to cool.
2. Meanwhile, poach the fish in enough water to just cover for 10 minutes. Drain and flake, carefully removing all bones and any skin.
3. Scoop the potato out of the skins and mash with the butter, milk, coriander or parsley, lemon zest and salt and pepper. Mix in the flaked fish and spring onion. With floured hands, shape into 8 round cakes. Beat the egg in a shallow bowl; place the crumbs in a separate bowl. Coat each cake with the egg, then the dried breadcrumbs and, ideally, leave in the fridge for about 30 minutes to firm up.
4. Heat the oil in a large frying pan over a medium heat and fry the fish cakes for about 5 minutes each side or until golden and crisp. Drain on kitchen paper and serve immediately.
MAKE IT VEGETARIAN Substitute 400g tin chickpeas for the salmon, omit the lemon zest and add 1 tsp sweet paprika and 1 tsp ground cumin