Melt margarine in a large saucepan.
Add leeks and prawns and saute for 2 minutes.
Add the wine.
In a jug, mix the KNORR Potato Bake together with the cold milk and stir until well combined.
Gradually add the milk mixture to the prawns, stirring until smooth.
Continue stirring over medium heat for 5 minutes or until the sauce has thickened slightly.
Stir in the cheese and cream.
Add seasonings and parsley and serve.