Roasting the Peanuts
Heat a wok over medium heat and add the oil. Introduce the peanuts and stir continuously to ensure even roasting, cooking for about 4-5 minutes.
Remove from heat and continue stirring for an additional minute with residual heat. Allow them to cool completely to achieve a crunchy texture. Alternatively, pre-roasted, unsalted peanuts may be used.
Preparing the Shrimp
Butterfly each shrimp by making a shallow incision along the back, ensuring not to cut through entirely. Transfer to a bowl and mix with oil, Shaoxing wine, salt, and white pepper powder. Let marinate for 15 minutes.
Just before cooking, coat the shrimp evenly with cornstarch.
Making the Sauce
In a small bowl, combine water, rice wine vinegar, both soy sauces, sugar, cornstarch, and Sichuan peppercorn powder. Stir thoroughly to ensure an even mixture.
Cooking the Dish
Heat a wok over high heat until it begins to smoke lightly. Add 2 tablespoons of oil, followed by the shrimp. Stir-fry quickly on both sides until they turn light pink, then transfer to a separate bowl.
Reduce heat to low and add the remaining tablespoon of oil. Stir in the garlic, ginger, dried chilies, and scallions, sautéing for 1-2 minutes until fragrant.
Increase heat and return the shrimp to the wok. Stir-fry for 30 seconds, then re-stir the sauce to prevent cornstarch from settling. Pour the sauce into the wok, stirring continuously for another minute until it thickens.
Incorporate the roasted peanuts, mix thoroughly, and remove from heat. Serve immediately.