Slightly butter the inside of a 2-pint (1 litre) pudding dish
Place the jam/preserve or fruit in the bottom of the dish
Mix the flour and sugar in a thick saucepan over heat
Gradually add the milk, stirring well.
Cut the butter into small pieces
Add to the mixture
Stir until the mixture boils and thickens
Allow to cool slightly
Add the lemon or vanilla
Add the well-beaten eggs.
Beat until smooth
Pour evenly over the jam/preserve or fruit.
Brown in a pre-heated, moderate oven at 350°F/180°C/Gas Mark 4, for about 20 minutes.