Hypothesis Testing

The following nice story comes from R.A. Fisher [Fis60]. At a social gathering, a lady X claims: If she is served a cup of tea with some milk added, she can generally taste perfectly whether the tea or the milk was poured first. How do you test this claim? Certainly not like this: Present two completely identical cups, in the first of which milk and then tea (order MT) was poured first, and in the second tea and then milk (TM) was poured. If you now let the lady choose, she obviously has a 50% chance of giving the correct answer, even if her claim is false.