Add the potatoes to a large pan and cover with water. Bring to the boil, cover and simmer until tender (approx. 10-15 mins)
Drain the potatoes, return them to the pan, shake briefly and allow them to steam dry for around 30 seconds. Mash until smooth and allow to cool.
Add the tuna, spring onion, lime juice, coriander (cilantro) and stir until combined, breaking up any larger pieces of tuna. Taste the mixture and season accordingly (do not salt if making for baby)
Mould into equal rounds. I used an ice-cream scoop and made 17. You can make them bigger if preferred.
Press/ roll in the breadcrumbs until coated. (See notes if you wish to achieve a thicker, crispier coating)
COOKING OPTION 1: Add the oil to frying pan over medium-high heat. Once hot, carefully place patties in the pan (do not overcrowd you will need to cook in batches). Fry for 3-4mins (or until golden) then flip and fry until golden on the other side.
COOKING OPTION 2: Place on a lined baking sheet and spray with oil. Bake at 200C/400F for 20-25mins or until golden and crispy. Turn halfway through the cooking time and spray the other side of the fish cakes before returning to the oven. (Timings may vary depending on the size of patties).