In a small bowl dissolve cornflour in 1/4 cup dry white wine. Set aside.
In a large frypan heat peanut oil (on medium-high heat) until almost smoking. Remove the frypan from heat and add spring onions. Return the frypan to heat and cook, stirring constantly until the spring onions are soft.
Add the scallops to the frypan. Cook the scallops for 1 minute, stirring constantly.
Add fish stock to the frypan. Continue stirring. Add salt and cayenne to taste. Stir in ginger and water chestnuts.
Stir in the mixture of dissolved cornflour and white wine. Turn the heat to high and cook the mixture until it boils and thickens.