Bring a pan of water to the boil and add the potatoes. Boil for 20–25 minutes until softened. Drain, then return to the pan and mash until smooth.
Allow the mashed potato to cool to a temperature that is comfortable to handle.
Separate the chunks of jackfruit into strands, discarding any tough parts. Add the strands to the pan along with the mayonnaise, spring onions and parsley. Season with salt and pepper, then stir to combine all of the ingredients.
Once combined, take heaped tablespoon-sized amounts of the mixture and shape into patties about 5–6cm (2–21⁄2in) in diameter. Place on a plate, then refrigerate for 1 hour(this will help to firm them up for easier cooking).
Heat the sunflower oil in a frying pan until hot. Carefully add up to four of the patties to the pan and cook over a medium–high heat for 5 minutes until golden, then use tongs to turn them over and cook for a further 5 minutes.
Remove from the pan and keep warm while you cook the remaining no-fish cakes. Serve hot. Cook the no-fish cakes in two batches to avoid overfilling the pan, making turning easier and ensuring even cooking.