What is Tarte tatin?

The name given to a classic French apple tart in which the fruit is cooked under a lid of pastry, but served upside down - with the pastry underneath and the fruit on top. It combines the taste of caramel with the flavour of apples cooked in butter and was made famous by the Tatin sisters who ran a hotel-restaurant in France in the early 1900s.

Many variations of the original apple 'upside-down' tart have since been developed, including savoury versions using shallots or onions.