On a plate or tray, mix the salt and cornstarch. Add the shrimp and toss until they are lightly coated.
salt and pepper, to taste, 125 g cornstarch
In a small bowl, combine the salt and ground Sichuan pepper.
1 teaspoon salt, 1 teaspoon Sichuan peppercorns
Heat 1.5 cm of oil in a medium skillet or wok over medium-high heat until it reaches 190 °C. If you don't have a thermometer, dip a wooden spoon into the oil: small bubbles should quickly form around the cornstarch.
neutral oil
Add the shrimp to the pan one by one in a single layer. Hold each shrimp by the tail, shake off excess cornstarch, and gently lower it into the oil. Cook in batches if needed. Fry about 2 minutes per side, until pale golden and curled.
Transfer the shrimp to a wire rack to drain.
Once all the shrimp are cooked, pour off the remaining oil into a bowl, leaving just a little in the pan. Remove any coating residue or it will burn.
Add the garlic and chilies to the wok over medium-high heat. Stir-fry for 1 to 2 minutes, until fragrant.
6 cloves garlic, 2 red chilies
Add the shrimp and sprinkle with the salt-and-pepper mixture. Toss until evenly coated.
Transfer to a plate and garnish with scallions.
scallions, thinly sliced
Notes
It's really important to remove any coating residue, even if that means discarding all the oil or switching pans/woks. If it burns, it will ruin the flavor. (Speaking from experience—RIP the shrimp from test no. 2.)