Heat olive oil in a large frypan over medium heat. Stir in onions and cook until they turn golden brown, about 10 minutes. Stir in the garlic and ginger, cook for 1 minute, then pour in wine and bring to a boil.
Add the prawns and cook until they begin to turn pink, about 3 minutes. Add snow peas and cook until they begin to soften, about 2 minutes. Season to taste with salt and pepper. Stir in chopped coriander and serve immediately.