Cook the potatoes in boiling water for 10 minutes until tender, drain and allow to cool.
Meanwhile, poach the salmon and eggs in boiling water for 10 minutes, cool. Flake the salmon and chop the boiled eggs.
Mash the potato and stir in the salmon, egg, spring onions, half the dill and mint, season. Mould into 8 fishcakes and chill for 30 minutes.
Meanwhile, mix together the crème fraiche, mayonnaise and the remaining dill and set aside.
Heat the oil in a large frying pan and fry the fishcakes in 2 batches for 3-4 minutes each side until golden. Serve with the dill dip and a green salad.