4 heaped tablespoons of redcurrant jelly
4 tablespoons port
1 heaped teaspoon of mustard powder
1 heaped teaspoon ground ginger
Now place the redcurrant jelly in a saucepan with the port and melt, whisking them together over a low heat for about 5 or 10 minutes.
In a serving bowl, mix the mustard and ginger with the juice of half the lemon until smooth, then add the juice of the whole orange, the port and redcurrant mixture, and finally the strips of lemon and orange zest. Mix well and the sauce is ready to use.
Cumberland sauce stores well in a screw-top jar in the refrigerator for up to two weeks.