Cook the potatoes in a saucepan of lightly salted boiling water for 12 minutes until soft. Drain well and roughly mash.
Meanwhile, rub 1 teaspoon of the oil over the salmon and season well. Cook under a preheated hot grill for 10 minutes until cooked through. Leave to cool a little, then break into large flakes. Mix together the ingredients for the sauce.
Mix together the potato, salmon, dill and lemon rind. Lightly wet your hands, then shape into 8 fishcakes. Dust each fishcake with a little flour, dip into the egg and finally dip into the breadcrumbs until well coated.
Heat the remaining oil in a large, nonstick frying pan. Cook the fishcakes for 3–4 minutes on each side until golden and crisp. Serve with a green salad and the dill sauce.