Rinse shrimp and drain well, toss in cornstarch and shake off excess. Heat wok over high heat.
When wok is very hot, turn stove fan on high. Add oil and garlic and stir together briefly. Add shrimp and toss to coat, cooking 1 minute.
Add Chinese rice wine, cover, reduce heat to medium and simmer 1-2 minutes. Remove lid, add soy sauce, white pepper and onions and mix well, Cook until sauce is nearly absorbed.
Serve immediately with rice and vegetables.