Take the squid tubes and clean off any residue, and then slice them, make a cut from the tip to the base and open them up. Then trim the top and bottom edges if required.Cut a crosshatch pattern (5-6mm ¼" apart) on the inside face of the squid, ensuring that you do not cut all of the way through.Once scored, cut the squid into 3cm (1¼") squares.
Heat a dry wok (or frying pan) over a high heat and when it is hot, toast the Szechuan peppercorns for 2-3 minutes, keeping them moving all of the time. Transfer to a pestle and mortar or spice grinder and grind along with the black peppercorns.
De-seed the chilli pepper and dice it as finely as you can.
Peel the garlic cloves and chop them as finely as you can.
Finely shred the spring onions.
Dry the squid pieces thoroughly and place them in a bowl with the cornflower.
Heat 3-4cm (1½-1¾") of oil in a wok to 180°C or 350°F.
Pat the excess cornflour from the squid and deep fry for 2-3 mins. This is best done in two batches.Drain on a kitchen towel.
Pour the hot oil into a separate pan with the exception of a scant coating.
Add the salt, peppers, garlic and chilli stir fry for 10 seconds. Add the squid, toss to coat and then serve sprinkled with the spring onions and lemon wedges.