Remove head and shell of prawns, clean with salt, rinse with water and pat dry. Slice each prawn crosswise into 4 pieces. Marinate in wine, cornstarch, salt, and egg white in a bowl for 30 minutes.
Stir-fry green vegetable in 3 tablespoons oil and ½ teaspoon salt. Remove and drain, arrange on serving platter in a “Y” shape.