Whisk together the flour and egg, and then add the chopped spring onions, sweetcorn, finely chopped chilli, and fresh coriander. Mix to combine, and season generously.
Dice the avocado, and add it to the mixture along with the lemon / lime juice. Stir gently until well mixed.
Heat the oil in a frying pan, and add a heaped tablespoon of the batter. Flatten it out slightly, and shape into a circle, before repeating with the remaining mixture - I ended up with 5 fritters in total, but you could make 4 or 6 fritters if you prefer. Depending on the size of your pan, you might need to do two batches.
Cook over a medium-low heat for around 5 minutes, until golden brown underneath. Carefully turn the fritters with a spatula, and repeat with the other side. Serve immediately.