Orange and Lemon Sauce
grated zest and juice of 2 large oranges or lemons
1 tbsp cornflour (cornstarch)
2 tbsp sugar
a knob of butter
1 medium egg yolk (optional)
1 Put the fruit zest and juice in a bowl and make up to 300ml/½ pint/1¼ cups with water. Blend the cornflour and sugar with a little of the liquid until smooth.
2 Heat the remaining liquid until boiling, then pour on to the blended mixture, stirring all the time. Return to the pan and bring to the boil, stirring until the sauce thickens. Stir in the butter.
3 Cool, then beat in the egg yolk, if using, and reheat, stirring, without boiling.