1. Slit the tubes down the one side to open it out, scrape out anything that looks like it should not be there, rinse under cold water and, pat dry.
2. Place on a flat surface and score the inside of the tube in a diamond pattern.
3. Now cut the squid into rectangles about 2.5cm.
4. Mix the potato flour with salt and pepper and cayenne pepper.
5. Toss the squid in the seasoned potato flour.
6. Shallow fry till golden.
7. Remove and drain on paper towel.
8. Serve on a platter with sweet chilli sauce and finely chopped spring onions.