Choose a new cookbook worth up to £28 when you subscribe to our magazine.
Put the potatoes in a saucepan, cover in cold, salted water and bring to the boil. Once boiling reduce to a simmer and cook for about 8 mins until tender. Drain and leave to steam-dry for 2 mins.
Mash the potatoes in a large bowl. Add the tuna and combine, breaking it up with a fork, then add the lemon juice and chives. Season well, add the egg and use your hands to bring everything together. Divide the mixture into 6 and shape into fishcakes. Chill for 10 mins to firm up.
Meanwhile, mix the spring onions with the mayonnaise and chill until ready to serve. To cook the fishcakes, heat half the oil in a large non-stick pan and lightly dust the fishcakes with flour. Cook half for 3-4 mins each side until golden and warmed through, then repeat with the rest of the fishcakes.
Serve with the mayonnaise, a lemon wedge and some mixed leaves.