01 - Pat the shrimp completely dry with paper towels. In a mixing bowl, toss shrimp with 1/2 tsp salt, white pepper, and black pepper. Let sit for 5 minutes to allow flavors to penetrate.
02 - Toss the seasoned shrimp in cornstarch until lightly coated. Shake off any excess starch to prevent clumping during frying.
03 - Heat vegetable oil in a wok or deep skillet over medium-high heat. When hot, fry shrimp in batches without overcrowding for 2–3 minutes per batch until golden and crisp. Remove with a slotted spoon and drain on paper towels.
04 - Carefully pour off most of the oil, leaving about 1 tablespoon in the pan. Add garlic and chili; stir-fry for 30 seconds until fragrant but not browned.
05 - Return shrimp to the pan, add scallions, Sichuan peppercorns, and remaining 1/2 tsp salt. Toss everything together over high heat for 1 minute until well mixed and heated through.
06 - Serve immediately with lemon wedges on the side for squeezing over the crispy shrimp.