2) Open the vine leaves on a work surface and place 3 next to each other, then 2 below these and overlapping them, and then 1 below those and overlapping, making the shape of a large vine leaf, widest end towards you.
3) Place a piece of salmon on the vine leaves, spread with some seasoned mayonnaise and top with some of the feta. Fold the leaves, from the wide end, over the salmon, then fold in both sides and the top. Repeat with the remaining ingredients.
4) Coat a large frying pan with olive oil. Place the pan over a medium heat and fry the four parcels until the salmon is cooked through. Transfer to warmed serving plates and garnish with a slices of lemon.