1-1/2 Tablespoons Sugar
1 Tablespoon Mustard
2 Teaspoons Cornflour
1/2 Cup Vinegar
1/2 Cup Stock from the Corned Beef
Beat egg,sugar,mustard and cornflour until smooth.
Whisk in the vinegar and stock.
Cook in a double boiler or tip into a heavy based saucepan Microwave and stir continuously until the mixture thickens. Simmer slowly 15 minutes or longer.
Add freshly ground pepper.