Begin by combining fresh or thawed prawns with soy sauce and sesame oil in a medium bowl. Toss the prawns thoroughly and let them rest for about 10 minutes.

In a dry frying pan over medium heat, toast Sichuan peppercorns for 2-3 minutes until fragrant, then grind into a fine powder.

Slice the pale part of the spring onions finely and cut the green tops into batons. Set aside.

In a small bowl, combine light soy sauce, Chinese Shaoxing wine, and sugar. Stir until well-blended.

Heat vegetable oil in a large pan over high heat. Dust the marinated prawns with plain flour and fry for 2-3 minutes per side until golden brown.

In the same pan, sauté minced garlic, grated ginger, sliced red chillies, and the white parts of the spring onions for 1 minute until fragrant.

Return the crispy prawns to the pan, sprinkle with ground Sichuan peppercorn, and drizzle the stir-fry sauce, mixing well.

Sprinkle the green tops of the spring onions over the dish and serve hot, ideally with steamed jasmine rice or garlic stir-fried bok choy.