In a mixing bowl, mix the tuna, cold mashed potato, fried onion, mayonnaise, egg, chopped green chillies and herbs until well combined. Season to taste.
Shape into patties and coat them lightly in plain flour and chill in the fridge for approx 30 minutes.
Heat enough oil for shallow frying in a medium-sized frying pan.
Fry the fishcakes over moderate heat until golden on both sides.
Place the fried fishcakes onto a plate lined with a paper towel to absorb excess oil.
Serve with tartar sauce, lemon wedges and a green salad.
Recipe by SAPeople South African Recipes at https://tastyrecipes.staging.sapeople.com/tuna-chilli-fish-cakes/