Finely chop the lemongrass, and place it in a bowl along with the sliced spring onions, julienned lime leaves, and chopped coriander.
Place the fish, fish sauce, red curry paste, breadcrumbs, red chili, lime juice, egg, and sugar in your food processor bowl, and pulse to purée the mixture into a sticky paste. Scrape down the sides as needed.
Add the fish mixture into the bowl and mix with a spatula until nicely combined.
Have a bowl of cold water to wet your hands and shape the mixture into patties to avoid the fish mixture sticking to your hands. You will have 16 fishcake sizes of approximately 45 grams each.
Place a large skillet or heavy-based on medium heat and add some oil, just enough to cover the base of the pan.
When the oil is hot enough, carefully place the patties in the pan. Do it in 2 or 3 batches to avoid overcrowding the pan.
Fry the patties for 2-3 minutes, until nicely browned, flip, and then fry the other side for another few minutes.
Repeat the same with the remaining patties and let them cool down for 10 minutes before serving.