Prepare the squid by scoring the inside surface in a diamond pattern, then slicing the tubes into bite-sized triangular pieces or rings.

Toast the Szechuan peppercorns and sea salt in a dry frying pan over medium heat for 2-3 minutes until fragrant, then grind them into a fine powder using a mortar and pestle.

Whisk the egg white in a medium bowl until slightly frothy, then toss the squid pieces in the egg white to coat them lightly.

Place the cornstarch in a shallow dish and dredge each piece of squid, shaking off any excess powder to ensure a thin, even coating.

Heat the vegetable oil in a wok or deep heavy-bottomed pot to 375°F (190°C).

Fry the squid in small batches for about 2-3 minutes per batch until the coating is golden brown and crispy.

Remove the cooked squid with a slotted spoon and drain on a wire rack or paper towels to remove excess oil.

Carefully pour out most of the oil from the wok, leaving about 1 tablespoon behind.

Add the minced garlic, sliced red chilies, and green onions to the hot wok and stir-fry for 30 seconds until aromatic.

Return the fried squid to the wok, sprinkle generously with the Szechuan salt and pepper mixture, and toss vigorously for 30 seconds to coat evenly.

Serve immediately while hot and crispy, optionally garnished with extra fresh chili slices.