Preheat the oven to 110°C (225°F/Gas ½) and lightly grease four 150ml (5fl oz) capacity dariole moulds with oil.
Combine all of the ingredients and whisk well. Pour into the moulds (they should only be half full). Place into a bain-marie filled with warm water and bake for 20 minutes. When the custards are just set (there should be a slight wobble), remove from the oven and from the bain-marie.