Chop the fish pie mix as finely as possible. Alternatively, pop it in a food processor and pulse a couple of times till the pieces are about ½cm in size, but not puréed.
Thinly slice 1 salad onion. Crack the egg into a medium bowl and beat. Add 1 tbsp Thai red curry paste and the sliced salad onion. Zest in 1 lemon. Beat together. Toss the fish pieces in 1 tbsp cornflour then add to the bowl. Mix well. Set aside.
Now make your hot and sour avocado salad. Zest the unzested lemon and squeeze the juice from both. Whisk with ½ tsp caster sugar. Add ½ tbsp oil and a good pinch of salt. Halve the chilli and flick out most of the seeds. Finely chop it. Add and whisk through the dressing. Set to one side.
Using a peeler, create ribbons of cucumber, turning the cucumber as you go. Stop when you get to the seeded middle. Finely chop that. Place in the bowl with the dressing.
Finely slice the remaining salad onion and add it to the bowl. Halve the cherry tomatoes and pop them into the bowl as well. Halve the avocado and remove the flesh. Thinly slice it and add to the bowl with the dressing. Gently toss together with the broccoli sprouts.
Set a frying pan on a medium high heat for a few mins. When warm, drizzle in 1 tbsp oil. Using a dessert spoon, scoop spoonfuls of the fritter mix carefully into the pan. Lightly press each fritter down to flatten it. Cook for 3 mins. Using a spatula or fish slice, flip the fritters over and cook for a further 2 mins. They should be golden and cooked through. Lift onto a plate lined with kitchen paper. You should make 8 fritters in total. You may need to do this in a couple of batches.
Serve the golden pan-fried Thai fish fritters with the crunchy hot and sour avocado salad.