Drain the can of salmon and remove any skin and bones, if wished. Break into chunks.
Heat 1tbsp vegetable oil in a frying pan and gently fry the red onion until soft, about 4 minutes.
Mash the chickpeas with a potato masher. Combine with the mashed potato, red onion, salmon, chives and parsley. Season with 1tsp paprika, 1tsp Jerk seasoning and some salt and pepper. Form the mixture into 4 burgers.
Put the flour onto a plate and mix in the rest of the paprika and Jerk seasoning with a little salt and pepper. Beat the egg in a shallow bowl.
Dip the burgers into the egg, then coat in the seasoned flour. Shallow fry in hot vegetable oil for 3-4 minutes per side.
Meanwhile, make the salsa by mixing together the pineapple, cucumber, red onion and sweet chilli sauce, adding fresh chilli, if using.
Toast or chargrill the cut sides of the burger buns. Add some lettuce, top with the burgers and serve with the salsa.