Method

Shell and split prawns, leaving tail intact. Coat with plain flour.

Sift self-raising flour into basin. Make well in centre. Break egg into this and work in some of the flour. Add water gradually, beating well to prevent lumping. Add mayonnaise. Dip prawns in batter and deep fry until golden brown. 

For the sauce: combine first 7 ingredients in a saucepan, heat.
Add blended cornflour, boil until thickened, boil for 3 minutes.

Serve with prawn cutlets.