Method

1. Heat the grill. Place the potatoes in a pan of water, bring to the boil, cover and cook for 12-15 mins until tender. Drain and leave to steam-dry, then mash. Meanwhile, season the salmon and grill for 5-6 mins until just cooked. Cool for a few mins, then break into large flakes.
2. Mix the potato, tomato sauce, mustard, zest, herbs and some seasoning. Lightly mix in the salmon, taking care not to break it up too much. Shape into 4 large fish cakes.
3. Put the flour, egg and breadcrumbs in 3 shallow dishes. Dip the cakes into the flour, dust off any excess, then dip in the egg, and finally coat in breadcrumbs. Heat the oil in a large pan. Fry the cakes over a medium-low heat for 3-4 mins each side until deep golden and heated through. Serve with salad and lemon wedges.

Variations

Make them into burgers:
Make and fry the salmon fish cakes as above. Meanwhile mix 4 tbsp Greek yogurt with 1 tbsp capers, 1 finely chopped shallot and a good squeeze lemon juice. Split 4 wholemeal baps and divide a good handful rocket between them. Thinly slice 1 large gherkin and divide between the buns, then add a hot salmon fish cake and a dollop of the caper yogurt to each.